diff --git a/Overlord-Client/cmd/agent/handlers/files_test.go b/Overlord-Client/cmd/agent/handlers/files_test.go
index 9252db6..4fc6346 100644
--- a/Overlord-Client/cmd/agent/handlers/files_test.go
+++ b/Overlord-Client/cmd/agent/handlers/files_test.go
@@ -3,6 +3,7 @@ package handlers
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -521,6 +522,72 @@ func TestHandleFileUploadHTTP(t *testing.T) {
 	}
 }
 
+func TestHandleFileUploadHTTP_ResumesWithRangeAfterShortRead(t *testing.T) {
+	data := bytes.Repeat([]byte("range-retry-"), 128*1024)
+	firstLen := len(data) / 3
+	var requests int
+	var sawRange string
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		requests++
+		if requests == 1 {
+			w.Header().Set("Content-Length", fmt.Sprintf("%d", len(data)))
+			_, _ = w.Write(data[:firstLen])
+			return
+		}
+
+		sawRange = r.Header.Get("Range")
+		expectedRange := fmt.Sprintf("bytes=%d-", firstLen)
+		if sawRange != expectedRange {
+			t.Fatalf("expected resume range %q, got %q", expectedRange, sawRange)
+		}
+		w.Header().Set("Content-Length", fmt.Sprintf("%d", len(data)-firstLen))
+		w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", firstLen, len(data)-1, len(data)))
+		w.WriteHeader(http.StatusPartialContent)
+		_, _ = w.Write(data[firstLen:])
+	}))
+	defer ts.Close()
+
+	tmpDir := t.TempDir()
+	destPath := filepath.Join(tmpDir, "uploaded-http-resume.bin")
+
+	writer := &testWriter{}
+	env := &rt.Env{
+		Conn: writer,
+		Cfg:  config.Config{TLSInsecureSkipVerify: true},
+	}
+
+	if err := HandleFileUploadHTTP(context.Background(), env, "cmd-http-upload-resume", destPath, ts.URL+"/file", int64(len(data))); err != nil {
+		t.Fatalf("HandleFileUploadHTTP failed: %v", err)
+	}
+
+	if requests < 2 {
+		t.Fatalf("expected retry request, got %d request(s)", requests)
+	}
+	if sawRange == "" {
+		t.Fatal("expected retry request to include Range header")
+	}
+
+	content, err := os.ReadFile(destPath)
+	if err != nil {
+		t.Fatalf("failed reading uploaded file: %v", err)
+	}
+	if !bytes.Equal(content, data) {
+		t.Fatalf("uploaded content mismatch after resume")
+	}
+
+	if len(writer.msgs) != 1 {
+		t.Fatalf("expected 1 message, got %d", len(writer.msgs))
+	}
+	var result wire.CommandResult
+	if err := msgpack.Unmarshal(writer.msgs[0], &result); err != nil {
+		t.Fatalf("failed to unmarshal command result: %v", err)
+	}
+	if !result.OK {
+		t.Fatalf("expected OK=true, got false: %s", result.Message)
+	}
+}
+
 func TestHandleFileUploadHTTP_SizeMismatch(t *testing.T) {
 	data := []byte("small")
 
diff --git a/Overlord-Server/public/assets/build-history-manager.js b/Overlord-Server/public/assets/build-history-manager.js
new file mode 100644
index 0000000..6a97c22
--- /dev/null
+++ b/Overlord-Server/public/assets/build-history-manager.js
@@ -0,0 +1,327 @@
+export function formatFileSize(bytes) {
+  if (bytes === 0) return "0 B";
+  const k = 1024;
+  const sizes = ["B", "KB", "MB", "GB"];
+  const i = Math.floor(Math.log(bytes) / Math.log(k));
+  return Math.round((bytes / Math.pow(k, i)) * 100) / 100 + " " + sizes[i];
+}
+
+function formatStubVersion(version) {
+  if (typeof version === "string" && version.trim()) {
+    return version.trim();
+  }
+  return "unknown (legacy build)";
+}
+
+function saveBuildToStorage(buildId, buildData) {
+  try {
+    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
+    const existingIndex = builds.findIndex((b) => b.id === buildId);
+
+    if (existingIndex >= 0) {
+      builds[existingIndex] = buildData;
+    } else {
+      builds.push(buildData);
+    }
+
+    if (builds.length > 20) {
+      builds.splice(0, builds.length - 20);
+    }
+
+    localStorage.setItem("overlord_builds", JSON.stringify(builds));
+  } catch (err) {
+    console.error("Failed to save build to localStorage:", err);
+  }
+}
+
+function getAllBuildsFromStorage() {
+  try {
+    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
+    return builds.sort((a, b) => b.startTime - a.startTime);
+  } catch (err) {
+    console.error("Failed to get builds from localStorage:", err);
+    return [];
+  }
+}
+
+function removeBuildFromStorage(buildId) {
+  try {
+    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
+    const filtered = builds.filter((b) => b.id !== buildId);
+    localStorage.setItem("overlord_builds", JSON.stringify(filtered));
+  } catch (err) {
+    console.error("Failed to remove build from localStorage:", err);
+  }
+}
+
+export function updateExpirationTimer(timerEl, expiresAt) {
+  if (!timerEl) return;
+
+  const now = Date.now();
+  const remaining = expiresAt - now;
+
+  if (remaining <= 0) {
+    timerEl.textContent = "Expired";
+    timerEl.className = "text-red-400 font-medium";
+    return;
+  }
+
+  const days = Math.floor(remaining / (1000 * 60 * 60 * 24));
+  const hours = Math.floor(
+    (remaining % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60),
+  );
+  const minutes = Math.floor((remaining % (1000 * 60 * 60)) / (1000 * 60));
+
+  if (days > 0) {
+    timerEl.textContent = `${days}d ${hours}h`;
+  } else if (hours > 0) {
+    timerEl.textContent = `${hours}h ${minutes}m`;
+  } else {
+    timerEl.textContent = `${minutes}m`;
+  }
+
+  if (days >= 3) {
+    timerEl.className = "text-green-400 font-medium";
+  } else if (days >= 1) {
+    timerEl.className = "text-yellow-400 font-medium";
+  } else {
+    timerEl.className = "text-orange-400 font-medium";
+  }
+}
+
+export function createBuildHistoryManager({
+  buildResults,
+  buildFilesDiv,
+  getCurrentServerVersion,
+  getCurrentUserRole,
+  getShowAllBuilds,
+}) {
+  function isVersionMismatch(versionValue) {
+    const currentServerVersion = getCurrentServerVersion();
+    if (!currentServerVersion) return false;
+    return versionValue !== currentServerVersion;
+  }
+
+  async function deleteBuild(buildId) {
+    if (!confirm("Are you sure you want to delete this build?")) {
+      return;
+    }
+
+    try {
+      const res = await fetch(`/api/build/${encodeURIComponent(buildId)}/delete`, {
+        method: "DELETE",
+        credentials: "include",
+      });
+
+      if (!res.ok) {
+        const data = await res.json().catch(() => ({}));
+        throw new Error(data.error || "Failed to delete build");
+      }
+
+      const buildElement = document.getElementById(`build-${buildId}`);
+      if (buildElement) {
+        buildElement.remove();
+      }
+
+      removeBuildFromStorage(buildId);
+
+      if (buildFilesDiv.children.length === 0) {
+        buildResults.classList.add("hidden");
+      }
+    } catch (err) {
+      console.error("Failed to delete build:", err);
+      alert("Failed to delete build. Please try again.");
+    }
+  }
+
+  async function loadSavedBuilds() {
+    try {
+      const queryParam =
+        getShowAllBuilds() && getCurrentUserRole() === "admin" ? "?all=true" : "";
+      const res = await fetch(`/api/build/list${queryParam}`, {
+        credentials: "include",
+      });
+
+      if (!res.ok) {
+        console.error("Failed to fetch builds from server");
+        return;
+      }
+
+      const data = await res.json();
+      const builds = data.builds || [];
+
+      const now = Date.now();
+      const validBuilds = builds.filter((build) => {
+        if (build.expiresAt && build.expiresAt <= now) {
+          return false;
+        }
+        return true;
+      });
+
+      if (validBuilds.length === 0) {
+        return;
+      }
+
+      buildResults.classList.remove("hidden");
+
+      for (const build of validBuilds) {
+        displayBuild(build);
+        saveBuildToStorage(build.id, build);
+      }
+    } catch (err) {
+      console.error("Failed to load builds:", err);
+
+      const builds = getAllBuildsFromStorage();
+      const now = Date.now();
+      const validBuilds = builds.filter((build) => {
+        if (build.expiresAt && build.expiresAt <= now) {
+          removeBuildFromStorage(build.id);
+          return false;
+        }
+        return true;
+      });
+
+      if (validBuilds.length > 0) {
+        buildResults.classList.remove("hidden");
+        validBuilds.forEach((build) => displayBuild(build));
+      }
+    }
+  }
+
+  function displayBuild(build) {
+    const buildContainer = document.createElement("div");
+    buildContainer.className =
+      "build-result-item mb-6 pb-6 border-b border-gray-700 last:border-b-0";
+    buildContainer.id = `build-${build.id}`;
+    const header = document.createElement("div");
+    header.className = "flex items-center justify-between mb-3";
+
+    const left = document.createElement("div");
+    left.className = "flex items-center gap-3";
+    const boxIcon = document.createElement("i");
+    boxIcon.className = "fa-solid fa-box text-blue-400";
+    const buildLabel = document.createElement("span");
+    buildLabel.className = "text-gray-300 font-medium";
+    buildLabel.textContent = `Build ID: ${build.id.substring(0, 8)}`;
+    const sep = document.createElement("span");
+    sep.className = "text-gray-500";
+    sep.textContent = "•";
+    const startedAt = document.createElement("span");
+    startedAt.className = "text-sm text-gray-400";
+    startedAt.textContent = new Date(build.startTime).toLocaleString();
+    left.appendChild(boxIcon);
+    left.appendChild(buildLabel);
+    left.appendChild(sep);
+    left.appendChild(startedAt);
+
+    const right = document.createElement("div");
+    right.className = "flex items-center gap-3";
+    const timerWrap = document.createElement("div");
+    timerWrap.className = "flex items-center gap-2";
+    const clockIcon = document.createElement("i");
+    clockIcon.className = "fa-solid fa-clock text-gray-400";
+    const timer = document.createElement("span");
+    timer.id = `timer-${build.id}`;
+    timer.className = "text-gray-300 font-medium";
+    timer.textContent = "Loading...";
+    timerWrap.appendChild(clockIcon);
+    timerWrap.appendChild(timer);
+
+    const deleteBtn = document.createElement("button");
+    deleteBtn.id = `delete-btn-${build.id}`;
+    deleteBtn.className =
+      "px-3 py-1.5 bg-red-500/20 hover:bg-red-500/30 text-red-400 rounded-lg transition-colors flex items-center gap-2 text-sm";
+    deleteBtn.title = "Delete build";
+    const deleteIcon = document.createElement("i");
+    deleteIcon.className = "fa-solid fa-trash";
+    const deleteText = document.createElement("span");
+    deleteText.textContent = "Delete";
+    deleteBtn.appendChild(deleteIcon);
+    deleteBtn.appendChild(deleteText);
+    deleteBtn.addEventListener("click", () => deleteBuild(build.id));
+
+    right.appendChild(timerWrap);
+    right.appendChild(deleteBtn);
+
+    header.appendChild(left);
+    header.appendChild(right);
+
+    const filesContainer = document.createElement("div");
+    filesContainer.id = `files-${build.id}`;
+    filesContainer.className = "space-y-2";
+
+    buildContainer.appendChild(header);
+    buildContainer.appendChild(filesContainer);
+
+    buildFilesDiv.appendChild(buildContainer);
+
+    showBuildFilesForContainer(build, `files-${build.id}`, `timer-${build.id}`);
+  }
+
+  function showBuildFilesForContainer(build, containerId, timerId) {
+    const container = document.getElementById(containerId);
+    const timerEl = document.getElementById(timerId);
+
+    if (!container || !timerEl) return;
+
+    build.files.forEach((file) => {
+      const fileDiv = document.createElement("div");
+      fileDiv.className =
+        "flex items-center justify-between bg-gray-700/50 p-4 rounded-lg hover:bg-gray-700 transition-colors";
+
+      const fileMeta = document.createElement("div");
+      fileMeta.className = "flex items-center gap-3";
+      const fileIcon = document.createElement("i");
+      fileIcon.className = "fa-solid fa-file text-blue-400";
+      const fileText = document.createElement("div");
+      const fileName = document.createElement("div");
+      fileName.className = "text-white font-medium";
+      fileName.textContent = file.filename;
+      const filePlatform = document.createElement("div");
+      filePlatform.className = "text-sm text-gray-400";
+      const versionValue = formatStubVersion(file.version);
+      const platformText = document.createElement("span");
+      platformText.textContent = `${file.platform} | `;
+      const versionText = document.createElement("span");
+      versionText.className = isVersionMismatch(versionValue)
+        ? "server-version-number-mismatch"
+        : "server-version-number";
+      versionText.textContent =
+        versionValue === "unknown (legacy build)" ? versionValue : `v${versionValue}`;
+      filePlatform.appendChild(platformText);
+      filePlatform.appendChild(versionText);
+      fileText.appendChild(fileName);
+      fileText.appendChild(filePlatform);
+      fileMeta.appendChild(fileIcon);
+      fileMeta.appendChild(fileText);
+
+      const download = document.createElement("a");
+      download.href = `/api/build/download/${encodeURIComponent(file.filename)}`;
+      download.download = "";
+      download.className =
+        "px-4 py-2 bg-blue-500 hover:bg-blue-600 text-white rounded-lg transition-colors flex items-center gap-2";
+      const downloadIcon = document.createElement("i");
+      downloadIcon.className = "fa-solid fa-download";
+      const downloadText = document.createElement("span");
+      downloadText.textContent = "Download";
+      download.appendChild(downloadIcon);
+      download.appendChild(downloadText);
+
+      fileDiv.appendChild(fileMeta);
+      fileDiv.appendChild(download);
+
+      container.appendChild(fileDiv);
+    });
+
+    if (build.expiresAt) {
+      updateExpirationTimer(timerEl, build.expiresAt);
+      setInterval(() => updateExpirationTimer(timerEl, build.expiresAt), 60000);
+    }
+  }
+
+  return {
+    displayBuild,
+    loadSavedBuilds,
+    saveBuildToStorage,
+  };
+}
diff --git a/Overlord-Server/public/assets/build-profile-manager.js b/Overlord-Server/public/assets/build-profile-manager.js
new file mode 100644
index 0000000..20583f8
--- /dev/null
+++ b/Overlord-Server/public/assets/build-profile-manager.js
@@ -0,0 +1,243 @@
+const PROFILE_EXPORT_MAGIC = "overlord-build-profile";
+
+function sanitizeProfileName(name) {
+  if (typeof name !== "string") return "";
+  const trimmed = name.trim();
+  if (!trimmed || trimmed.length > 64) return "";
+  if (!/^[A-Za-z0-9 _.-]+$/.test(trimmed)) return "";
+  return trimmed;
+}
+
+function exportProfileToFile(name, config) {
+  const payload = {
+    type: PROFILE_EXPORT_MAGIC,
+    version: 1,
+    name,
+    exportedAt: Date.now(),
+    config,
+  };
+  const json = JSON.stringify(payload, null, 2);
+  const blob = new Blob([json], { type: "application/json" });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement("a");
+  const safeName = (name || "build-profile").replace(/[^A-Za-z0-9._-]/g, "_");
+  a.href = url;
+  a.download = `${safeName}.json`;
+  document.body.appendChild(a);
+  a.click();
+  a.remove();
+  URL.revokeObjectURL(url);
+}
+
+export function createBuildProfileManager({
+  elements,
+  collectFormSettings,
+  applyFormSettings,
+  saveFormSettings,
+}) {
+  const {
+    profileSelect,
+    profileNameInput,
+    profileSaveBtn,
+    profileLoadBtn,
+    profileDeleteBtn,
+    profileExportBtn,
+    profileImportBtn,
+    profileImportFile,
+  } = elements;
+
+  let buildProfiles = [];
+
+  function renderProfileOptions(selectedName = "") {
+    if (!profileSelect) return;
+    profileSelect.innerHTML = "";
+
+    const placeholder = document.createElement("option");
+    placeholder.value = "";
+    placeholder.textContent = "Select a saved profile...";
+    profileSelect.appendChild(placeholder);
+
+    buildProfiles.forEach((profile) => {
+      const option = document.createElement("option");
+      option.value = profile.name;
+      option.textContent = profile.name;
+      if (selectedName && selectedName === profile.name) option.selected = true;
+      profileSelect.appendChild(option);
+    });
+  }
+
+  function getSelectedProfile() {
+    if (!profileSelect || !profileSelect.value) return null;
+    return buildProfiles.find((profile) => profile.name === profileSelect.value) || null;
+  }
+
+  async function loadBuildProfiles(selectedName = "") {
+    try {
+      const res = await fetch("/api/build/profiles", { credentials: "include" });
+      if (!res.ok) {
+        buildProfiles = [];
+        renderProfileOptions();
+        return;
+      }
+      const data = await res.json();
+      buildProfiles = Array.isArray(data?.profiles) ? data.profiles : [];
+      renderProfileOptions(selectedName || profileSelect?.value || "");
+    } catch (err) {
+      console.error("Failed to load build profiles:", err);
+      buildProfiles = [];
+      renderProfileOptions();
+    }
+  }
+
+  async function saveCurrentProfile() {
+    const inputName = profileNameInput?.value || "";
+    const selectedName = profileSelect?.value || "";
+    const profileName = sanitizeProfileName(inputName || selectedName);
+    if (!profileName) {
+      alert("Enter a valid profile name (1-64 chars; letters, numbers, spaces, . _ -)");
+      profileNameInput?.focus();
+      return;
+    }
+
+    const config = collectFormSettings();
+
+    const res = await fetch("/api/build/profiles", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      credentials: "include",
+      body: JSON.stringify({ name: profileName, config }),
+    });
+
+    if (!res.ok) {
+      const data = await res.json().catch(() => ({}));
+      throw new Error(data.error || "Failed to save profile");
+    }
+
+    if (profileNameInput) profileNameInput.value = profileName;
+    await loadBuildProfiles(profileName);
+  }
+
+  async function importProfileFromFile(file) {
+    const text = await file.text();
+    let parsed;
+    try {
+      parsed = JSON.parse(text);
+    } catch {
+      throw new Error("Invalid JSON file");
+    }
+
+    const fallbackName = file.name.replace(/\.json$/i, "");
+    const importedName = sanitizeProfileName(parsed?.name || fallbackName);
+    if (!importedName) {
+      throw new Error("Invalid profile name in imported file");
+    }
+
+    const importedConfig = parsed?.config;
+    if (!importedConfig || typeof importedConfig !== "object" || Array.isArray(importedConfig)) {
+      throw new Error("Imported profile is missing a valid config object");
+    }
+
+    applyFormSettings(importedConfig);
+    saveFormSettings();
+
+    if (profileNameInput) profileNameInput.value = importedName;
+    await saveCurrentProfile();
+  }
+
+  function bindProfileControls() {
+    if (profileSelect) {
+      profileSelect.addEventListener("change", () => {
+        const profile = getSelectedProfile();
+        if (profileNameInput) {
+          profileNameInput.value = profile?.name || "";
+        }
+      });
+    }
+
+    if (profileSaveBtn) {
+      profileSaveBtn.addEventListener("click", async () => {
+        try {
+          await saveCurrentProfile();
+          alert("Profile saved.");
+        } catch (err) {
+          alert(err?.message || "Failed to save profile");
+        }
+      });
+    }
+
+    if (profileLoadBtn) {
+      profileLoadBtn.addEventListener("click", () => {
+        const profile = getSelectedProfile();
+        if (!profile) {
+          alert("Select a profile to load.");
+          return;
+        }
+        applyFormSettings(profile.config || {});
+        saveFormSettings();
+        if (profileNameInput) profileNameInput.value = profile.name;
+        alert(`Loaded profile: ${profile.name}`);
+      });
+    }
+
+    if (profileDeleteBtn) {
+      profileDeleteBtn.addEventListener("click", async () => {
+        const profile = getSelectedProfile();
+        if (!profile) {
+          alert("Select a profile to delete.");
+          return;
+        }
+        if (!confirm(`Delete profile \"${profile.name}\"?`)) {
+          return;
+        }
+        try {
+          const res = await fetch(`/api/build/profiles/${encodeURIComponent(profile.name)}`, {
+            method: "DELETE",
+            credentials: "include",
+          });
+          if (!res.ok) {
+            const data = await res.json().catch(() => ({}));
+            throw new Error(data.error || "Failed to delete profile");
+          }
+          await loadBuildProfiles();
+          if (profileNameInput) profileNameInput.value = "";
+          alert("Profile deleted.");
+        } catch (err) {
+          alert(err?.message || "Failed to delete profile");
+        }
+      });
+    }
+
+    if (profileExportBtn) {
+      profileExportBtn.addEventListener("click", () => {
+        const profile = getSelectedProfile();
+        if (profile) {
+          exportProfileToFile(profile.name, profile.config || {});
+          return;
+        }
+        const fallbackName = sanitizeProfileName(profileNameInput?.value || "") || "current-build-profile";
+        exportProfileToFile(fallbackName, collectFormSettings());
+      });
+    }
+
+    if (profileImportBtn && profileImportFile) {
+      profileImportBtn.addEventListener("click", () => profileImportFile.click());
+      profileImportFile.addEventListener("change", async () => {
+        const file = profileImportFile.files?.[0];
+        profileImportFile.value = "";
+        if (!file) return;
+        try {
+          await importProfileFromFile(file);
+          alert("Profile imported and saved.");
+        } catch (err) {
+          alert(err?.message || "Failed to import profile");
+        }
+      });
+    }
+  }
+
+  return {
+    bindProfileControls,
+    loadBuildProfiles,
+    sanitizeProfileName,
+  };
+}
diff --git a/Overlord-Server/public/assets/build.js b/Overlord-Server/public/assets/build.js
index 2cad010..4453492 100644
--- a/Overlord-Server/public/assets/build.js
+++ b/Overlord-Server/public/assets/build.js
@@ -1,3 +1,10 @@
+import { createBuildProfileManager } from "./build-profile-manager.js";
+import {
+  createBuildHistoryManager,
+  formatFileSize,
+  updateExpirationTimer,
+} from "./build-history-manager.js";
+
 const form = document.getElementById("build-form");
 const buildBtn = document.getElementById("build-btn");
 const buildStatus = document.getElementById("build-status");
@@ -39,6 +46,7 @@ const platformInputs = document.querySelectorAll('input[name="platform"]');
 
 let currentServerVersion = null;
 let currentUserRole = null;
+let showAllBuilds = false;
 
 async function loadServerVersion() {
   try {
@@ -115,9 +123,6 @@ function updateWindowsSectionVisibility() {
 }
 
 const BUILD_SETTINGS_KEY = "overlord_build_settings";
-const PROFILE_EXPORT_MAGIC = "overlord-build-profile";
-
-let buildProfiles = [];
 
 function collectFormSettings() {
   return {
@@ -285,130 +290,35 @@ function restoreFormSettings() {
   }
 }
 
-function sanitizeProfileName(name) {
-  if (typeof name !== "string") return "";
-  const trimmed = name.trim();
-  if (!trimmed || trimmed.length > 64) return "";
-  if (!/^[A-Za-z0-9 _.-]+$/.test(trimmed)) return "";
-  return trimmed;
-}
+const buildProfileManager = createBuildProfileManager({
+  elements: {
+    profileSelect,
+    profileNameInput,
+    profileSaveBtn,
+    profileLoadBtn,
+    profileDeleteBtn,
+    profileExportBtn,
+    profileImportBtn,
+    profileImportFile,
+  },
+  collectFormSettings,
+  applyFormSettings,
+  saveFormSettings,
+});
+const { loadBuildProfiles } = buildProfileManager;
 
-function renderProfileOptions(selectedName = "") {
-  if (!profileSelect) return;
-  profileSelect.innerHTML = "";
-
-  const placeholder = document.createElement("option");
-  placeholder.value = "";
-  placeholder.textContent = "Select a saved profile...";
-  profileSelect.appendChild(placeholder);
-
-  buildProfiles.forEach((profile) => {
-    const option = document.createElement("option");
-    option.value = profile.name;
-    option.textContent = profile.name;
-    if (selectedName && selectedName === profile.name) option.selected = true;
-    profileSelect.appendChild(option);
-  });
-}
-
-function getSelectedProfile() {
-  if (!profileSelect || !profileSelect.value) return null;
-  return buildProfiles.find((profile) => profile.name === profileSelect.value) || null;
-}
-
-async function loadBuildProfiles(selectedName = "") {
-  try {
-    const res = await fetch("/api/build/profiles", { credentials: "include" });
-    if (!res.ok) {
-      buildProfiles = [];
-      renderProfileOptions();
-      return;
-    }
-    const data = await res.json();
-    buildProfiles = Array.isArray(data?.profiles) ? data.profiles : [];
-    renderProfileOptions(selectedName || profileSelect?.value || "");
-  } catch (err) {
-    console.error("Failed to load build profiles:", err);
-    buildProfiles = [];
-    renderProfileOptions();
-  }
-}
-
-async function saveCurrentProfile() {
-  const inputName = profileNameInput?.value || "";
-  const selectedName = profileSelect?.value || "";
-  const profileName = sanitizeProfileName(inputName || selectedName);
-  if (!profileName) {
-    alert("Enter a valid profile name (1-64 chars; letters, numbers, spaces, . _ -)");
-    profileNameInput?.focus();
-    return;
-  }
-
-  const config = collectFormSettings();
-
-  const res = await fetch("/api/build/profiles", {
-    method: "POST",
-    headers: { "Content-Type": "application/json" },
-    credentials: "include",
-    body: JSON.stringify({ name: profileName, config }),
-  });
-
-  if (!res.ok) {
-    const data = await res.json().catch(() => ({}));
-    throw new Error(data.error || "Failed to save profile");
-  }
-
-  if (profileNameInput) profileNameInput.value = profileName;
-  await loadBuildProfiles(profileName);
-}
-
-function exportProfileToFile(name, config) {
-  const payload = {
-    type: PROFILE_EXPORT_MAGIC,
-    version: 1,
-    name,
-    exportedAt: Date.now(),
-    config,
-  };
-  const json = JSON.stringify(payload, null, 2);
-  const blob = new Blob([json], { type: "application/json" });
-  const url = URL.createObjectURL(blob);
-  const a = document.createElement("a");
-  const safeName = (name || "build-profile").replace(/[^A-Za-z0-9._-]/g, "_");
-  a.href = url;
-  a.download = `${safeName}.json`;
-  document.body.appendChild(a);
-  a.click();
-  a.remove();
-  URL.revokeObjectURL(url);
-}
-
-async function importProfileFromFile(file) {
-  const text = await file.text();
-  let parsed;
-  try {
-    parsed = JSON.parse(text);
-  } catch {
-    throw new Error("Invalid JSON file");
-  }
-
-  const fallbackName = file.name.replace(/\.json$/i, "");
-  const importedName = sanitizeProfileName(parsed?.name || fallbackName);
-  if (!importedName) {
-    throw new Error("Invalid profile name in imported file");
-  }
-
-  const importedConfig = parsed?.config;
-  if (!importedConfig || typeof importedConfig !== "object" || Array.isArray(importedConfig)) {
-    throw new Error("Imported profile is missing a valid config object");
-  }
-
-  applyFormSettings(importedConfig);
-  saveFormSettings();
-
-  if (profileNameInput) profileNameInput.value = importedName;
-  await saveCurrentProfile();
-}
+const buildHistoryManager = createBuildHistoryManager({
+  buildResults,
+  buildFilesDiv,
+  getCurrentServerVersion: () => currentServerVersion,
+  getCurrentUserRole: () => currentUserRole,
+  getShowAllBuilds: () => showAllBuilds,
+});
+const {
+  displayBuild,
+  loadSavedBuilds,
+  saveBuildToStorage,
+} = buildHistoryManager;
 
 const CRYPTABLE_DISABLE_TARGETS = [
   'input[name="enable-persistence"]',
@@ -1419,94 +1329,7 @@ if (logoutBtn && !logoutBtn.dataset.boundLogout) {
   });
 }
 
-if (profileSelect) {
-  profileSelect.addEventListener("change", () => {
-    const profile = getSelectedProfile();
-    if (profileNameInput) {
-      profileNameInput.value = profile?.name || "";
-    }
-  });
-}
-
-if (profileSaveBtn) {
-  profileSaveBtn.addEventListener("click", async () => {
-    try {
-      await saveCurrentProfile();
-      alert("Profile saved.");
-    } catch (err) {
-      alert(err?.message || "Failed to save profile");
-    }
-  });
-}
-
-if (profileLoadBtn) {
-  profileLoadBtn.addEventListener("click", () => {
-    const profile = getSelectedProfile();
-    if (!profile) {
-      alert("Select a profile to load.");
-      return;
-    }
-    applyFormSettings(profile.config || {});
-    saveFormSettings();
-    if (profileNameInput) profileNameInput.value = profile.name;
-    alert(`Loaded profile: ${profile.name}`);
-  });
-}
-
-if (profileDeleteBtn) {
-  profileDeleteBtn.addEventListener("click", async () => {
-    const profile = getSelectedProfile();
-    if (!profile) {
-      alert("Select a profile to delete.");
-      return;
-    }
-    if (!confirm(`Delete profile \"${profile.name}\"?`)) {
-      return;
-    }
-    try {
-      const res = await fetch(`/api/build/profiles/${encodeURIComponent(profile.name)}`, {
-        method: "DELETE",
-        credentials: "include",
-      });
-      if (!res.ok) {
-        const data = await res.json().catch(() => ({}));
-        throw new Error(data.error || "Failed to delete profile");
-      }
-      await loadBuildProfiles();
-      if (profileNameInput) profileNameInput.value = "";
-      alert("Profile deleted.");
-    } catch (err) {
-      alert(err?.message || "Failed to delete profile");
-    }
-  });
-}
-
-if (profileExportBtn) {
-  profileExportBtn.addEventListener("click", () => {
-    const profile = getSelectedProfile();
-    if (profile) {
-      exportProfileToFile(profile.name, profile.config || {});
-      return;
-    }
-    const fallbackName = sanitizeProfileName(profileNameInput?.value || "") || "current-build-profile";
-    exportProfileToFile(fallbackName, collectFormSettings());
-  });
-}
-
-if (profileImportBtn && profileImportFile) {
-  profileImportBtn.addEventListener("click", () => profileImportFile.click());
-  profileImportFile.addEventListener("change", async () => {
-    const file = profileImportFile.files?.[0];
-    profileImportFile.value = "";
-    if (!file) return;
-    try {
-      await importProfileFromFile(file);
-      alert("Profile imported and saved.");
-    } catch (err) {
-      alert(err?.message || "Failed to import profile");
-    }
-  });
-}
+buildProfileManager.bindProfileControls();
 
 form?.addEventListener("submit", async (e) => {
   e.preventDefault();
@@ -2078,8 +1901,8 @@ function showBuildFiles(files, buildId, expiresAt) {
   buildInfoDiv.appendChild(infoRow);
   buildFilesDiv.appendChild(buildInfoDiv);
 
-  updateExpirationTimer();
-  setInterval(updateExpirationTimer, 60000);
+  updateExpirationTimer(timer, expiresAt);
+  setInterval(() => updateExpirationTimer(timer, expiresAt), 60000);
 
   files.forEach((file) => {
     const fileDiv = document.createElement("div");
@@ -2112,333 +1935,6 @@ function showBuildFiles(files, buildId, expiresAt) {
   });
 }
 
-function updateExpirationTimer(timerEl, expiresAt) {
-  if (!timerEl) return;
-
-  const now = Date.now();
-  const remaining = expiresAt - now;
-
-  if (remaining <= 0) {
-    timerEl.textContent = "Expired";
-    timerEl.className = "text-red-400 font-medium";
-    return;
-  }
-
-  const days = Math.floor(remaining / (1000 * 60 * 60 * 24));
-  const hours = Math.floor(
-    (remaining % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60),
-  );
-  const minutes = Math.floor((remaining % (1000 * 60 * 60)) / (1000 * 60));
-
-  if (days > 0) {
-    timerEl.textContent = `${days}d ${hours}h`;
-  } else if (hours > 0) {
-    timerEl.textContent = `${hours}h ${minutes}m`;
-  } else {
-    timerEl.textContent = `${minutes}m`;
-  }
-
-  if (days >= 3) {
-    timerEl.className = "text-green-400 font-medium";
-  } else if (days >= 1) {
-    timerEl.className = "text-yellow-400 font-medium";
-  } else {
-    timerEl.className = "text-orange-400 font-medium";
-  }
-}
-
-async function deleteBuild(buildId) {
-  if (!confirm("Are you sure you want to delete this build?")) {
-    return;
-  }
-
-  try {
-    const res = await fetch(`/api/build/${encodeURIComponent(buildId)}/delete`, {
-      method: "DELETE",
-      credentials: "include",
-    });
-
-    if (!res.ok) {
-      const data = await res.json().catch(() => ({}));
-      throw new Error(data.error || "Failed to delete build");
-    }
-
-    const buildElement = document.getElementById(`build-${buildId}`);
-    if (buildElement) {
-      buildElement.remove();
-    }
-
-    removeBuildFromStorage(buildId);
-
-    if (buildFilesDiv.children.length === 0) {
-      buildResults.classList.add("hidden");
-    }
-  } catch (err) {
-    console.error("Failed to delete build:", err);
-    alert("Failed to delete build. Please try again.");
-  }
-}
-
-function formatFileSize(bytes) {
-  if (bytes === 0) return "0 B";
-  const k = 1024;
-  const sizes = ["B", "KB", "MB", "GB"];
-  const i = Math.floor(Math.log(bytes) / Math.log(k));
-  return Math.round((bytes / Math.pow(k, i)) * 100) / 100 + " " + sizes[i];
-}
-
-function formatStubVersion(version) {
-  if (typeof version === "string" && version.trim()) {
-    return version.trim();
-  }
-  return "unknown (legacy build)";
-}
-
-function isVersionMismatch(versionValue) {
-  if (!currentServerVersion) return false;
-  return versionValue !== currentServerVersion;
-}
-
-function saveBuildToStorage(buildId, buildData) {
-  try {
-    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
-    const existingIndex = builds.findIndex((b) => b.id === buildId);
-
-    if (existingIndex >= 0) {
-      builds[existingIndex] = buildData;
-    } else {
-      builds.push(buildData);
-    }
-
-    if (builds.length > 20) {
-      builds.splice(0, builds.length - 20);
-    }
-
-    localStorage.setItem("overlord_builds", JSON.stringify(builds));
-  } catch (err) {
-    console.error("Failed to save build to localStorage:", err);
-  }
-}
-
-function getBuildFromStorage(buildId) {
-  try {
-    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
-    return builds.find((b) => b.id === buildId);
-  } catch (err) {
-    console.error("Failed to get build from localStorage:", err);
-    return null;
-  }
-}
-
-function getAllBuildsFromStorage() {
-  try {
-    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
-
-    return builds.sort((a, b) => b.startTime - a.startTime);
-  } catch (err) {
-    console.error("Failed to get builds from localStorage:", err);
-    return [];
-  }
-}
-
-function removeBuildFromStorage(buildId) {
-  try {
-    const builds = JSON.parse(localStorage.getItem("overlord_builds") || "[]");
-    const filtered = builds.filter((b) => b.id !== buildId);
-    localStorage.setItem("overlord_builds", JSON.stringify(filtered));
-  } catch (err) {
-    console.error("Failed to remove build from localStorage:", err);
-  }
-}
-
-let showAllBuilds = false;
-
-async function loadSavedBuilds() {
-  try {
-    const queryParam = showAllBuilds && currentUserRole === "admin" ? "?all=true" : "";
-    const res = await fetch(`/api/build/list${queryParam}`, {
-      credentials: "include",
-    });
-
-    if (!res.ok) {
-      console.error("Failed to fetch builds from server");
-      return;
-    }
-
-    const data = await res.json();
-    const builds = data.builds || [];
-
-    const now = Date.now();
-    const validBuilds = builds.filter((build) => {
-      if (build.expiresAt && build.expiresAt <= now) {
-        return false;
-      }
-      return true;
-    });
-
-    if (validBuilds.length === 0) {
-      return;
-    }
-
-    buildResults.classList.remove("hidden");
-
-    for (const build of validBuilds) {
-      displayBuild(build);
-
-      saveBuildToStorage(build.id, build);
-    }
-  } catch (err) {
-    console.error("Failed to load builds:", err);
-
-    const builds = getAllBuildsFromStorage();
-    const now = Date.now();
-    const validBuilds = builds.filter((build) => {
-      if (build.expiresAt && build.expiresAt <= now) {
-        removeBuildFromStorage(build.id);
-        return false;
-      }
-      return true;
-    });
-
-    if (validBuilds.length > 0) {
-      buildResults.classList.remove("hidden");
-      validBuilds.forEach((build) => displayBuild(build));
-    }
-  }
-}
-
-function displayBuild(build) {
-  const buildContainer = document.createElement("div");
-  buildContainer.className =
-    "build-result-item mb-6 pb-6 border-b border-gray-700 last:border-b-0";
-  buildContainer.id = `build-${build.id}`;
-  const header = document.createElement("div");
-  header.className = "flex items-center justify-between mb-3";
-
-  const left = document.createElement("div");
-  left.className = "flex items-center gap-3";
-  const boxIcon = document.createElement("i");
-  boxIcon.className = "fa-solid fa-box text-blue-400";
-  const buildLabel = document.createElement("span");
-  buildLabel.className = "text-gray-300 font-medium";
-  buildLabel.textContent = `Build ID: ${build.id.substring(0, 8)}`;
-  const sep = document.createElement("span");
-  sep.className = "text-gray-500";
-  sep.textContent = "•";
-  const startedAt = document.createElement("span");
-  startedAt.className = "text-sm text-gray-400";
-  startedAt.textContent = new Date(build.startTime).toLocaleString();
-  left.appendChild(boxIcon);
-  left.appendChild(buildLabel);
-  left.appendChild(sep);
-  left.appendChild(startedAt);
-
-  const right = document.createElement("div");
-  right.className = "flex items-center gap-3";
-  const timerWrap = document.createElement("div");
-  timerWrap.className = "flex items-center gap-2";
-  const clockIcon = document.createElement("i");
-  clockIcon.className = "fa-solid fa-clock text-gray-400";
-  const timer = document.createElement("span");
-  timer.id = `timer-${build.id}`;
-  timer.className = "text-gray-300 font-medium";
-  timer.textContent = "Loading...";
-  timerWrap.appendChild(clockIcon);
-  timerWrap.appendChild(timer);
-
-  const deleteBtn = document.createElement("button");
-  deleteBtn.id = `delete-btn-${build.id}`;
-  deleteBtn.className =
-    "px-3 py-1.5 bg-red-500/20 hover:bg-red-500/30 text-red-400 rounded-lg transition-colors flex items-center gap-2 text-sm";
-  deleteBtn.title = "Delete build";
-  const deleteIcon = document.createElement("i");
-  deleteIcon.className = "fa-solid fa-trash";
-  const deleteText = document.createElement("span");
-  deleteText.textContent = "Delete";
-  deleteBtn.appendChild(deleteIcon);
-  deleteBtn.appendChild(deleteText);
-  deleteBtn.addEventListener("click", () => deleteBuild(build.id));
-
-  right.appendChild(timerWrap);
-  right.appendChild(deleteBtn);
-
-  header.appendChild(left);
-  header.appendChild(right);
-
-  const filesContainer = document.createElement("div");
-  filesContainer.id = `files-${build.id}`;
-  filesContainer.className = "space-y-2";
-
-  buildContainer.appendChild(header);
-  buildContainer.appendChild(filesContainer);
-
-  buildFilesDiv.appendChild(buildContainer);
-
-  showBuildFilesForContainer(build, `files-${build.id}`, `timer-${build.id}`);
-}
-
-function showBuildFilesForContainer(build, containerId, timerId) {
-  const container = document.getElementById(containerId);
-  const timerEl = document.getElementById(timerId);
-
-  if (!container || !timerEl) return;
-
-  build.files.forEach((file) => {
-    const fileDiv = document.createElement("div");
-    fileDiv.className =
-      "flex items-center justify-between bg-gray-700/50 p-4 rounded-lg hover:bg-gray-700 transition-colors";
-
-    const fileMeta = document.createElement("div");
-    fileMeta.className = "flex items-center gap-3";
-    const fileIcon = document.createElement("i");
-    fileIcon.className = "fa-solid fa-file text-blue-400";
-    const fileText = document.createElement("div");
-    const fileName = document.createElement("div");
-    fileName.className = "text-white font-medium";
-    fileName.textContent = file.filename;
-    const filePlatform = document.createElement("div");
-    filePlatform.className = "text-sm text-gray-400";
-    const versionValue = formatStubVersion(file.version);
-    const platformText = document.createElement("span");
-    platformText.textContent = `${file.platform} | `;
-    const versionText = document.createElement("span");
-    versionText.className = isVersionMismatch(versionValue)
-      ? "server-version-number-mismatch"
-      : "server-version-number";
-    versionText.textContent =
-      versionValue === "unknown (legacy build)" ? versionValue : `v${versionValue}`;
-    filePlatform.appendChild(platformText);
-    filePlatform.appendChild(versionText);
-    fileText.appendChild(fileName);
-    fileText.appendChild(filePlatform);
-    fileMeta.appendChild(fileIcon);
-    fileMeta.appendChild(fileText);
-
-    const download = document.createElement("a");
-    download.href = `/api/build/download/${encodeURIComponent(file.filename)}`;
-    download.download = "";
-    download.className =
-      "px-4 py-2 bg-blue-500 hover:bg-blue-600 text-white rounded-lg transition-colors flex items-center gap-2";
-    const downloadIcon = document.createElement("i");
-    downloadIcon.className = "fa-solid fa-download";
-    const downloadText = document.createElement("span");
-    downloadText.textContent = "Download";
-    download.appendChild(downloadIcon);
-    download.appendChild(downloadText);
-
-    fileDiv.appendChild(fileMeta);
-    fileDiv.appendChild(download);
-
-    container.appendChild(fileDiv);
-  });
-
-  if (build.expiresAt) {
-    updateExpirationTimer(timerEl, build.expiresAt);
-
-    setInterval(() => updateExpirationTimer(timerEl, build.expiresAt), 60000);
-  }
-}
-
 const buildUpdateAllBtn = document.getElementById("build-update-all-btn");
 const updateAllModal = document.getElementById("update-all-modal");
 const updateAllModalBody = document.getElementById("update-all-modal-body");
diff --git a/Overlord-Server/public/assets/filebrowser-hex-hash.js b/Overlord-Server/public/assets/filebrowser-hex-hash.js
new file mode 100644
index 0000000..44a2c91
--- /dev/null
+++ b/Overlord-Server/public/assets/filebrowser-hex-hash.js
@@ -0,0 +1,253 @@
+import { escapeHtml, formatBytes } from "./filebrowser-utils.js";
+
+const KNOWN_HASHES_SHA256 = {
+  "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855": "Empty file (0 bytes)",
+};
+
+function decodeTextHead(bytes) {
+  try {
+    return new TextDecoder("utf-8", { fatal: false }).decode(bytes);
+  } catch {
+    return new TextDecoder("latin1").decode(bytes);
+  }
+}
+
+export function createFileHexHashManager({
+  send,
+  notifyToast,
+  getCurrentPreviewEntry,
+}) {
+  const previewTextHeadHost = document.getElementById("preview-text-head-host");
+  const previewTextHead = document.getElementById("preview-text-head");
+  const previewHexBtn = document.getElementById("preview-hex-btn");
+  const previewHashBtn = document.getElementById("preview-hash-btn");
+  const previewHashResult = document.getElementById("preview-hash-result");
+  const previewHashValue = document.getElementById("preview-hash-value");
+  const previewHashKnown = document.getElementById("preview-hash-known");
+
+  const hexViewerModal = document.getElementById("hex-viewer-modal");
+  const hexViewerFile = document.getElementById("hex-viewer-file");
+  const hexViewerBody = document.getElementById("hex-viewer-body");
+  const hexViewerInfo = document.getElementById("hex-viewer-info");
+  const hexViewerCloseBtn = document.getElementById("hex-viewer-close-btn");
+  const hexViewerCopyBtn = document.getElementById("hex-viewer-copy-btn");
+
+  const peekRequests = new Map();
+  const hashRequests = new Map();
+  let lastHexBytes = null;
+
+  function resetPreviewTextHead() {
+    previewTextHeadHost?.classList.add("hidden");
+    if (previewTextHead) previewTextHead.textContent = "";
+  }
+
+  function resetPreviewHash() {
+    previewHashResult?.classList.add("hidden");
+    if (previewHashValue) previewHashValue.textContent = "";
+    if (previewHashKnown) {
+      previewHashKnown.classList.add("hidden");
+      previewHashKnown.textContent = "";
+    }
+  }
+
+  function requestFilePeek(path, kind) {
+    const commandId = `peek-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+    const fileName = path.split(/[\/\\]/).pop() || "";
+    peekRequests.set(commandId, { kind, path, fileName });
+    send({
+      type: "command",
+      commandType: "file_peek",
+      id: commandId,
+      payload: { path, bytes: 4096 },
+    });
+  }
+
+  function openHexViewer(path) {
+    if (!hexViewerModal) return;
+    const fileName = path.split(/[\/\\]/).pop() || "";
+    if (hexViewerFile) hexViewerFile.textContent = fileName;
+    if (hexViewerBody) hexViewerBody.innerHTML = '<div class="text-slate-400"><i class="fa-solid fa-circle-notch fa-spin mr-2"></i>Loading...</div>';
+    if (hexViewerInfo) hexViewerInfo.textContent = "";
+    hexViewerModal.classList.add("show");
+    requestFilePeek(path, "hex");
+  }
+
+  function closeHexViewer() {
+    hexViewerModal?.classList.remove("show");
+  }
+
+  function renderHexDump(bytes, totalSize) {
+    if (!hexViewerBody) return;
+    const len = bytes.length;
+    const rows = [];
+    for (let off = 0; off < len; off += 16) {
+      const chunk = bytes.slice(off, Math.min(off + 16, len));
+      const hexParts = [];
+      const asciiParts = [];
+      for (let i = 0; i < 16; i++) {
+        if (i < chunk.length) {
+          hexParts.push(chunk[i].toString(16).padStart(2, "0"));
+          const b = chunk[i];
+          if (b >= 0x20 && b <= 0x7e) {
+            asciiParts.push(`<span>${escapeHtml(String.fromCharCode(b))}</span>`);
+          } else {
+            asciiParts.push('<span class="np">.</span>');
+          }
+        } else {
+          hexParts.push("  ");
+          asciiParts.push(" ");
+        }
+        if (i === 7) hexParts.push("");
+      }
+      rows.push(
+        `<div class="hex-row">` +
+          `<span class="hex-off">${off.toString(16).padStart(8, "0")}</span>` +
+          `<span class="hex-bytes">${hexParts.join(" ")}</span>` +
+          `<span class="hex-ascii">${asciiParts.join("")}</span>` +
+        `</div>`,
+      );
+    }
+    hexViewerBody.innerHTML = rows.join("");
+    if (hexViewerInfo) {
+      const peekStr = `${formatBytes(len)} peek`;
+      const totalStr = totalSize > 0 ? ` of ${formatBytes(totalSize)}` : "";
+      hexViewerInfo.textContent = peekStr + totalStr;
+    }
+    lastHexBytes = bytes;
+  }
+
+  function handleFilePeekResult(msg) {
+    const req = msg.commandId ? peekRequests.get(msg.commandId) : null;
+    if (!req) return;
+    peekRequests.delete(msg.commandId);
+
+    const currentPreviewEntry = getCurrentPreviewEntry();
+    if (msg.error) {
+      if (req.kind === "hex") {
+        if (hexViewerBody) hexViewerBody.innerHTML = `<div class="text-red-400 p-3"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(msg.error)}</div>`;
+      }
+      if (req.kind === "preview" && currentPreviewEntry && currentPreviewEntry.path === req.path) {
+        previewTextHeadHost?.classList.add("hidden");
+      }
+      return;
+    }
+
+    let data = msg.data;
+    if (!data) data = new Uint8Array(0);
+    if (!(data instanceof Uint8Array)) {
+      try { data = new Uint8Array(data); } catch { data = new Uint8Array(0); }
+    }
+
+    if (req.kind === "hex") {
+      renderHexDump(data, Number(msg.size || 0));
+      return;
+    }
+
+    if (!currentPreviewEntry || currentPreviewEntry.path !== req.path) return;
+    if (!msg.isText || data.length === 0) {
+      previewTextHeadHost?.classList.add("hidden");
+      return;
+    }
+    const text = decodeTextHead(data);
+    if (previewTextHead) previewTextHead.textContent = text;
+    previewTextHeadHost?.classList.remove("hidden");
+  }
+
+  function requestFileHash(path, source) {
+    const commandId = `hash-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+    const fileName = path.split(/[\/\\]/).pop() || "";
+    hashRequests.set(commandId, { path, fileName, source });
+    send({
+      type: "command",
+      commandType: "file_hash",
+      id: commandId,
+      payload: { path, algorithm: "sha256" },
+    });
+    notifyToast(`Hashing ${fileName}...`, "info", 2500);
+  }
+
+  function handleFileHashResult(msg) {
+    const req = msg.commandId ? hashRequests.get(msg.commandId) : null;
+    if (!req) return;
+    hashRequests.delete(msg.commandId);
+
+    if (msg.error) {
+      notifyToast(`Hash failed: ${msg.error}`, "error", 5000);
+      return;
+    }
+    const digest = (msg.digest || "").toLowerCase();
+    const known = KNOWN_HASHES_SHA256[digest];
+    const currentPreviewEntry = getCurrentPreviewEntry();
+
+    if (currentPreviewEntry && currentPreviewEntry.path === req.path && previewHashValue) {
+      previewHashValue.textContent = digest;
+      previewHashResult?.classList.remove("hidden");
+      if (previewHashKnown) {
+        if (known) {
+          previewHashKnown.textContent = `Known: ${known}`;
+          previewHashKnown.classList.remove("hidden");
+        } else {
+          previewHashKnown.classList.add("hidden");
+        }
+      }
+    }
+
+    const msgSuffix = known ? ` - matches known: ${known}` : "";
+    notifyToast(`SHA-256: ${digest.slice(0, 16)}...${msgSuffix}`, "success", 6000);
+    navigator.clipboard?.writeText(digest).catch(() => {});
+  }
+
+  function bindControls() {
+    hexViewerCloseBtn?.addEventListener("click", closeHexViewer);
+    hexViewerModal?.addEventListener("click", (e) => {
+      if (e.target === hexViewerModal) closeHexViewer();
+    });
+    document.addEventListener("keydown", (e) => {
+      if (e.key === "Escape" && hexViewerModal?.classList.contains("show")) {
+        closeHexViewer();
+      }
+    });
+    hexViewerCopyBtn?.addEventListener("click", async () => {
+      if (!lastHexBytes) return;
+      const hex = Array.from(lastHexBytes).map((b) => b.toString(16).padStart(2, "0")).join("");
+      try {
+        await navigator.clipboard.writeText(hex);
+        notifyToast("Hex copied to clipboard", "success", 2000);
+      } catch {
+        notifyToast("Clipboard copy failed", "error", 2500);
+      }
+    });
+
+    previewHexBtn?.addEventListener("click", () => {
+      const currentPreviewEntry = getCurrentPreviewEntry();
+      if (currentPreviewEntry && !currentPreviewEntry.isDir) {
+        openHexViewer(currentPreviewEntry.path);
+      }
+    });
+    previewHashBtn?.addEventListener("click", () => {
+      const currentPreviewEntry = getCurrentPreviewEntry();
+      if (currentPreviewEntry && !currentPreviewEntry.isDir) {
+        requestFileHash(currentPreviewEntry.path, "preview");
+      }
+    });
+    previewHashValue?.addEventListener("click", async () => {
+      const v = previewHashValue.textContent || "";
+      if (!v) return;
+      try {
+        await navigator.clipboard.writeText(v);
+        notifyToast("SHA-256 copied", "success", 1500);
+      } catch {}
+    });
+  }
+
+  return {
+    bindControls,
+    handleFileHashResult,
+    handleFilePeekResult,
+    openHexViewer,
+    requestFileHash,
+    requestFilePeek,
+    resetPreviewHash,
+    resetPreviewTextHead,
+  };
+}
diff --git a/Overlord-Server/public/assets/filebrowser-preview-modal.js b/Overlord-Server/public/assets/filebrowser-preview-modal.js
new file mode 100644
index 0000000..2ab62c9
--- /dev/null
+++ b/Overlord-Server/public/assets/filebrowser-preview-modal.js
@@ -0,0 +1,166 @@
+import {
+  PREVIEW_IMAGE_EXTS,
+  PREVIEW_MAX_BYTES,
+  escapeHtml,
+  formatBytes,
+  getFileExt,
+  getPreviewMimeType,
+} from "./filebrowser-utils.js";
+
+export function createFilePreviewModal({
+  clientId,
+  notifyToast,
+  onDownload,
+}) {
+  const filePreviewModal = document.getElementById("file-preview-modal");
+  const previewFileNameEl = document.getElementById("preview-file-name");
+  const previewContent = document.getElementById("preview-content");
+  const previewCloseBtn = document.getElementById("preview-close-btn");
+  const previewDownloadBtn = document.getElementById("preview-download-btn");
+  const previewStatusEl = document.getElementById("preview-status");
+
+  let currentPreviewBlobUrl = null;
+  let currentPreviewPath = null;
+
+  function closePreview() {
+    if (filePreviewModal) filePreviewModal.classList.remove("show");
+    if (currentPreviewBlobUrl) {
+      URL.revokeObjectURL(currentPreviewBlobUrl);
+      currentPreviewBlobUrl = null;
+    }
+    if (previewContent) previewContent.innerHTML = "";
+    if (previewStatusEl) previewStatusEl.textContent = "";
+    currentPreviewPath = null;
+  }
+
+  async function openFilePreview(path, knownSize) {
+    const fileName = path.split(/[\/\\]/).pop() || "";
+    const mimeType = getPreviewMimeType(fileName);
+    if (!mimeType) return;
+
+    if (typeof knownSize === "number" && knownSize > PREVIEW_MAX_BYTES) {
+      notifyToast(`File too large to preview (${formatBytes(knownSize)})`, "info", 4000);
+      return;
+    }
+
+    currentPreviewPath = path;
+    if (previewFileNameEl) previewFileNameEl.textContent = fileName;
+    if (previewContent) previewContent.innerHTML = '<i class="fa-solid fa-circle-notch fa-spin text-slate-400 text-2xl"></i>';
+    if (previewStatusEl) previewStatusEl.textContent = "Loading...";
+    if (filePreviewModal) filePreviewModal.classList.add("show");
+
+    try {
+      const requestRes = await fetch("/api/file/download/request", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        credentials: "include",
+        body: JSON.stringify({ clientId, path }),
+      });
+
+      if (!requestRes.ok) {
+        const text = await requestRes.text();
+        if (currentPreviewPath !== path) return;
+        if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(text || "Failed to load preview")}</div>`;
+        if (previewStatusEl) previewStatusEl.textContent = "";
+        return;
+      }
+
+      const requestData = await requestRes.json();
+      const downloadUrl = typeof requestData?.downloadUrl === "string"
+        ? requestData.downloadUrl
+        : (requestData?.downloadId
+          ? `/api/file/download/${encodeURIComponent(requestData.downloadId)}`
+          : "");
+
+      if (!downloadUrl) {
+        if (currentPreviewPath !== path) return;
+        if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>Failed to load preview</div>`;
+        if (previewStatusEl) previewStatusEl.textContent = "";
+        return;
+      }
+
+      const res = await fetch(downloadUrl, {
+        method: "GET",
+        credentials: "include",
+      });
+
+      if (!res.ok) {
+        const text = await res.text();
+        if (currentPreviewPath !== path) return;
+        if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(text || "Failed to load preview")}</div>`;
+        if (previewStatusEl) previewStatusEl.textContent = "";
+        return;
+      }
+
+      const contentLength = Number(res.headers.get("Content-Length") || 0);
+      if (contentLength > PREVIEW_MAX_BYTES) {
+        if (currentPreviewPath !== path) return;
+        if (previewContent) previewContent.innerHTML = `<div class="text-slate-400 text-sm text-center p-6"><i class="fa-solid fa-file mr-2"></i>File too large to preview (${escapeHtml(formatBytes(contentLength))})</div>`;
+        if (previewStatusEl) previewStatusEl.textContent = "";
+        return;
+      }
+
+      const arrayBuffer = await res.arrayBuffer();
+
+      if (currentPreviewPath !== path) return;
+
+      if (arrayBuffer.byteLength > PREVIEW_MAX_BYTES) {
+        if (previewContent) previewContent.innerHTML = `<div class="text-slate-400 text-sm text-center p-6"><i class="fa-solid fa-file mr-2"></i>File too large to preview (${escapeHtml(formatBytes(arrayBuffer.byteLength))})</div>`;
+        if (previewStatusEl) previewStatusEl.textContent = "";
+        return;
+      }
+
+      if (currentPreviewBlobUrl) {
+        URL.revokeObjectURL(currentPreviewBlobUrl);
+        currentPreviewBlobUrl = null;
+      }
+
+      const blob = new Blob([arrayBuffer], { type: mimeType });
+      currentPreviewBlobUrl = URL.createObjectURL(blob);
+
+      if (previewContent) {
+        previewContent.innerHTML = "";
+        if (PREVIEW_IMAGE_EXTS.has(getFileExt(fileName))) {
+          const img = document.createElement("img");
+          img.src = currentPreviewBlobUrl;
+          img.alt = "";
+          previewContent.appendChild(img);
+        } else {
+          const obj = document.createElement("object");
+          obj.data = currentPreviewBlobUrl;
+          obj.type = "application/pdf";
+          previewContent.appendChild(obj);
+        }
+      }
+
+      if (previewStatusEl) previewStatusEl.textContent = "";
+    } catch (err) {
+      if (currentPreviewPath !== path) return;
+      if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(err.message || "Failed to load preview")}</div>`;
+      if (previewStatusEl) previewStatusEl.textContent = "";
+    }
+  }
+
+  function bindControls() {
+    if (previewCloseBtn) previewCloseBtn.addEventListener("click", closePreview);
+    if (previewDownloadBtn) previewDownloadBtn.addEventListener("click", () => {
+      if (currentPreviewPath) onDownload(currentPreviewPath);
+    });
+    if (filePreviewModal) {
+      filePreviewModal.addEventListener("click", (e) => {
+        if (e.target === filePreviewModal) closePreview();
+      });
+    }
+    document.addEventListener("keydown", (e) => {
+      if (e.key === "Escape" && filePreviewModal && filePreviewModal.classList.contains("show")) {
+        closePreview();
+      }
+    });
+  }
+
+  return {
+    bindControls,
+    closePreview,
+    openFilePreview,
+  };
+}
diff --git a/Overlord-Server/public/assets/filebrowser-transfer-panel.js b/Overlord-Server/public/assets/filebrowser-transfer-panel.js
new file mode 100644
index 0000000..d0cdc4d
--- /dev/null
+++ b/Overlord-Server/public/assets/filebrowser-transfer-panel.js
@@ -0,0 +1,80 @@
+import { formatBytes } from "./filebrowser-utils.js";
+
+export function createTransferPanel({ onCancel }) {
+  const transferPanel = document.getElementById("transfer-panel");
+  const transferList = document.getElementById("transfer-list");
+
+  function addTransferToUI(transfer) {
+    if (!transferPanel || !transferList) return;
+    const transferItem = document.createElement("div");
+    transferItem.id = `transfer-${transfer.id}`;
+    transferItem.className =
+      "transfer-item bg-slate-800/50 border border-slate-700 rounded-lg p-3";
+
+    const icon = transfer.type === "upload" ? "fa-upload" : "fa-download";
+    const color = transfer.type === "upload" ? "text-blue-400" : "text-green-400";
+
+    transferItem.innerHTML = `
+      <div class="flex items-center justify-between mb-2">
+        <div class="flex items-center gap-2 flex-1 min-w-0">
+          <i class="fa-solid ${icon} ${color}"></i>
+          <span class="text-sm truncate transfer-name"></span>
+        </div>
+        <button class="cancel-btn text-red-400 hover:text-red-300 px-2" type="button">
+          <i class="fa-solid fa-xmark"></i>
+        </button>
+      </div>
+      <div class="progress-bar-container w-full bg-slate-700 rounded-full h-2 mb-1">
+        <div class="progress-bar bg-blue-500 h-2 rounded-full transition-all duration-300" style="width: ${transfer.progress}%"></div>
+      </div>
+      <div class="flex justify-between text-xs text-slate-400">
+        <span class="progress-text">${transfer.progress}%</span>
+        <span class="size-text">${formatBytes(transfer.sent || transfer.received || 0)} / ${formatBytes(transfer.total)}</span>
+      </div>
+    `;
+
+    const nameEl = transferItem.querySelector(".transfer-name");
+    if (nameEl) {
+      nameEl.textContent = transfer.fileName;
+    }
+    const cancelBtn = transferItem.querySelector(".cancel-btn");
+    if (cancelBtn) {
+      cancelBtn.addEventListener("click", () => onCancel(transfer.id));
+    }
+
+    transferList.appendChild(transferItem);
+    transferPanel.classList.remove("hidden");
+  }
+
+  function updateTransferProgress(transferId, progress, current, total) {
+    const transferItem = document.getElementById(`transfer-${transferId}`);
+    if (!transferItem) return;
+
+    const progressBar = transferItem.querySelector(".progress-bar");
+    const progressText = transferItem.querySelector(".progress-text");
+    const sizeText = transferItem.querySelector(".size-text");
+
+    if (progressBar) progressBar.style.width = `${progress}%`;
+    if (progressText) progressText.textContent = `${progress}%`;
+    if (sizeText) {
+      sizeText.textContent = `${formatBytes(current)} / ${formatBytes(total)}`;
+    }
+  }
+
+  function removeTransfer(transferId) {
+    const transferItem = document.getElementById(`transfer-${transferId}`);
+    if (transferItem) {
+      transferItem.remove();
+    }
+
+    if (transferList && transferList.children.length === 0) {
+      transferPanel?.classList.add("hidden");
+    }
+  }
+
+  return {
+    addTransferToUI,
+    removeTransfer,
+    updateTransferProgress,
+  };
+}
diff --git a/Overlord-Server/public/assets/filebrowser-utils.js b/Overlord-Server/public/assets/filebrowser-utils.js
new file mode 100644
index 0000000..cf362ec
--- /dev/null
+++ b/Overlord-Server/public/assets/filebrowser-utils.js
@@ -0,0 +1,94 @@
+export function getFileExt(name = "") {
+  const idx = name.lastIndexOf(".");
+  if (idx < 0 || idx === name.length - 1) return "";
+  return name.slice(idx + 1).toLowerCase();
+}
+
+export const PREVIEW_IMAGE_EXTS = new Set(["jpg", "jpeg", "png", "gif", "webp", "bmp"]);
+export const PREVIEW_PDF_EXTS = new Set(["pdf"]);
+export const PREVIEW_MAX_BYTES = 50 * 1024 * 1024;
+
+export const KNOWN_BINARY_EXTS = new Set([
+  "mp4", "avi", "mkv", "mov", "wmv", "flv", "webm", "m4v",
+  "mp3", "wav", "flac", "ogg", "aac", "wma", "m4a",
+  "exe", "msi", "com", "app", "appimage",
+  "dll", "so", "dylib", "lib",
+  "zip", "rar", "7z", "tar", "gz", "bz2", "xz", "tgz",
+  "db", "sqlite", "sqlite3", "mdb",
+  "ttf", "otf", "woff", "woff2", "eot",
+  "iso", "img", "vhd", "vmdk",
+]);
+
+const IMAGE_MIME_MAP = {
+  jpg: "image/jpeg",
+  jpeg: "image/jpeg",
+  png: "image/png",
+  gif: "image/gif",
+  webp: "image/webp",
+  bmp: "image/bmp",
+};
+
+export function isPreviewable(name) {
+  const ext = getFileExt(name);
+  return PREVIEW_IMAGE_EXTS.has(ext) || PREVIEW_PDF_EXTS.has(ext);
+}
+
+export function getPreviewMimeType(name) {
+  const ext = getFileExt(name);
+  if (PREVIEW_PDF_EXTS.has(ext)) return "application/pdf";
+  return IMAGE_MIME_MAP[ext] || null;
+}
+
+export function shouldShowParentDirectory(path) {
+  if (!path || path === ".") {
+    return false;
+  }
+
+  return true;
+}
+
+export function getParentPath(path) {
+  const normalized = path.replace(/\\/g, "/");
+  const parts = normalized.split("/").filter((p) => p);
+
+  if (parts.length === 1 && parts[0].match(/^[A-Za-z]:$/)) {
+    return ".";
+  }
+
+  if (parts.length <= 1) {
+    return ".";
+  }
+
+  parts.pop();
+  let parentPath = parts.join("/");
+
+  if (parentPath.match(/^[A-Za-z]:?$/)) {
+    return parentPath.replace(/^([A-Za-z]):?$/, "$1:\\");
+  }
+
+  return parentPath || ".";
+}
+
+export function formatBytes(bytes) {
+  if (bytes === 0 || bytes === 0n) return "0 B";
+  const sizes = ["B", "KB", "MB", "GB", "TB"];
+  if (typeof bytes === "bigint") {
+    const k = 1024n;
+    let i = 0;
+    let value = bytes;
+    while (value >= k && i < sizes.length - 1) {
+      value /= k;
+      i += 1;
+    }
+    return `${value.toString()} ${sizes[i]}`;
+  }
+  const k = 1024;
+  const i = Math.floor(Math.log(bytes) / Math.log(k));
+  return Math.round((bytes / Math.pow(k, i)) * 100) / 100 + " " + sizes[i];
+}
+
+export function escapeHtml(text) {
+  const div = document.createElement("div");
+  div.textContent = text;
+  return div.innerHTML;
+}
diff --git a/Overlord-Server/public/assets/filebrowser.js b/Overlord-Server/public/assets/filebrowser.js
index 44df093..2923f4b 100644
--- a/Overlord-Server/public/assets/filebrowser.js
+++ b/Overlord-Server/public/assets/filebrowser.js
@@ -1,5 +1,18 @@
 import { encodeMsgpack, decodeMsgpack } from "./msgpack-helpers.js";
 import { checkFeatureAccess } from "./feature-gate.js";
+import { createFileHexHashManager } from "./filebrowser-hex-hash.js";
+import { createFilePreviewModal } from "./filebrowser-preview-modal.js";
+import { createTransferPanel } from "./filebrowser-transfer-panel.js";
+import {
+  KNOWN_BINARY_EXTS,
+  PREVIEW_IMAGE_EXTS,
+  escapeHtml,
+  formatBytes,
+  getFileExt,
+  getParentPath,
+  isPreviewable,
+  shouldShowParentDirectory,
+} from "./filebrowser-utils.js";
 
 const clientId = window.location.pathname.split("/")[1];
 let ws = null;
@@ -11,8 +24,6 @@ let fileUploads = new Map();
 let fileUploadsById = new Map();
 let activeTransfers = new Map();
 let currentEditingFile = null;
-let currentPreviewBlobUrl = null;
-let currentPreviewPath = null;
 let lastSuccessfulResponse = 0;
 let pendingToast = null;
 const recentToasts = new Map();
@@ -43,8 +54,6 @@ const backBtn = document.getElementById("back-btn");
 const homeBtn = document.getElementById("home-btn");
 const pathInput = document.getElementById("path-input");
 const pathGoBtn = document.getElementById("path-go-btn");
-const transferPanel = document.getElementById("transfer-panel");
-const transferList = document.getElementById("transfer-list");
 const fileListPanel = document.getElementById("file-list-panel");
 const sortFieldEl = document.getElementById("sort-field");
 const sortOrderBtn = document.getElementById("sort-order-btn");
@@ -72,12 +81,6 @@ const editorStatus = document.getElementById("editor-status");
 const editorSaveBtn = document.getElementById("editor-save-btn");
 const editorCancelBtn = document.getElementById("editor-cancel-btn");
 const editorCloseBtn = document.getElementById("editor-close-btn");
-const filePreviewModal = document.getElementById("file-preview-modal");
-const previewFileNameEl = document.getElementById("preview-file-name");
-const previewContent = document.getElementById("preview-content");
-const previewCloseBtn = document.getElementById("preview-close-btn");
-const previewDownloadBtn = document.getElementById("preview-download-btn");
-const previewStatusEl = document.getElementById("preview-status");
 
 if (clientIdHeader) {
   clientIdHeader.textContent = `${clientId} - File Browser`;
@@ -364,168 +367,19 @@ function updateBreadcrumb(path) {
   });
 }
 
-function getFileExt(name = "") {
-  const idx = name.lastIndexOf(".");
-  if (idx < 0 || idx === name.length - 1) return "";
-  return name.slice(idx + 1).toLowerCase();
-}
-
-
-const PREVIEW_IMAGE_EXTS = new Set(["jpg", "jpeg", "png", "gif", "webp", "bmp"]);
-const PREVIEW_PDF_EXTS = new Set(["pdf"]);
-const PREVIEW_MAX_BYTES = 50 * 1024 * 1024;
-
-// list of binary files from chatgpt (I can't think of anything else either)
-const KNOWN_BINARY_EXTS = new Set([
-  "mp4", "avi", "mkv", "mov", "wmv", "flv", "webm", "m4v",
-  "mp3", "wav", "flac", "ogg", "aac", "wma", "m4a",
-  "exe", "msi", "com", "app", "appimage",
-  "dll", "so", "dylib", "lib",
-  "zip", "rar", "7z", "tar", "gz", "bz2", "xz", "tgz",
-  "db", "sqlite", "sqlite3", "mdb",
-  "ttf", "otf", "woff", "woff2", "eot",
-  "iso", "img", "vhd", "vmdk",
-]);
-
-const IMAGE_MIME_MAP = {
-  jpg: "image/jpeg",
-  jpeg: "image/jpeg",
-  png: "image/png",
-  gif: "image/gif",
-  webp: "image/webp",
-  bmp: "image/bmp",
-};
-
-function isPreviewable(name) {
-  const ext = getFileExt(name);
-  return PREVIEW_IMAGE_EXTS.has(ext) || PREVIEW_PDF_EXTS.has(ext);
-}
-
-function getPreviewMimeType(name) {
-  const ext = getFileExt(name);
-  if (PREVIEW_PDF_EXTS.has(ext)) return "application/pdf";
-  return IMAGE_MIME_MAP[ext] || null;
-}
-
-function closePreview() {
-  if (filePreviewModal) filePreviewModal.classList.remove("show");
-  if (currentPreviewBlobUrl) {
-    URL.revokeObjectURL(currentPreviewBlobUrl);
-    currentPreviewBlobUrl = null;
-  }
-  if (previewContent) previewContent.innerHTML = "";
-  if (previewStatusEl) previewStatusEl.textContent = "";
-  currentPreviewPath = null;
-}
-
-async function openFilePreview(path, knownSize) {
-  const fileName = path.split(/[\/\\]/).pop() || "";
-  const mimeType = getPreviewMimeType(fileName);
-  if (!mimeType) return;
-
-  if (typeof knownSize === "number" && knownSize > PREVIEW_MAX_BYTES) {
-    notifyToast(`File too large to preview (${formatBytes(knownSize)})`, "info", 4000);
-    return;
-  }
-
-  currentPreviewPath = path;
-  if (previewFileNameEl) previewFileNameEl.textContent = fileName;
-  if (previewContent) previewContent.innerHTML = '<i class="fa-solid fa-circle-notch fa-spin text-slate-400 text-2xl"></i>';
-  if (previewStatusEl) previewStatusEl.textContent = "Loading...";
-  if (filePreviewModal) filePreviewModal.classList.add("show");
-
-  try {
-    const requestRes = await fetch("/api/file/download/request", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      credentials: "include",
-      body: JSON.stringify({ clientId, path }),
-    });
-
-    if (!requestRes.ok) {
-      const text = await requestRes.text();
-      if (currentPreviewPath !== path) return;
-      if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(text || "Failed to load preview")}</div>`;
-      if (previewStatusEl) previewStatusEl.textContent = "";
-      return;
-    }
-
-    const requestData = await requestRes.json();
-    const downloadUrl = typeof requestData?.downloadUrl === "string"
-      ? requestData.downloadUrl
-      : (requestData?.downloadId
-        ? `/api/file/download/${encodeURIComponent(requestData.downloadId)}`
-        : "");
-
-    if (!downloadUrl) {
-      if (currentPreviewPath !== path) return;
-      if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>Failed to load preview</div>`;
-      if (previewStatusEl) previewStatusEl.textContent = "";
-      return;
-    }
-
-    const res = await fetch(downloadUrl, {
-      method: "GET",
-      credentials: "include",
-    });
-
-    if (!res.ok) {
-      const text = await res.text();
-      if (currentPreviewPath !== path) return;
-      if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(text || "Failed to load preview")}</div>`;
-      if (previewStatusEl) previewStatusEl.textContent = "";
-      return;
-    }
-
-    // Reject oversized files before buffering to prevent OOM.
-    const contentLength = Number(res.headers.get("Content-Length") || 0);
-    if (contentLength > PREVIEW_MAX_BYTES) {
-      if (currentPreviewPath !== path) return;
-      if (previewContent) previewContent.innerHTML = `<div class="text-slate-400 text-sm text-center p-6"><i class="fa-solid fa-file mr-2"></i>File too large to preview (${escapeHtml(formatBytes(contentLength))})</div>`;
-      if (previewStatusEl) previewStatusEl.textContent = "";
-      return;
-    }
-
-    const arrayBuffer = await res.arrayBuffer();
-
-    if (currentPreviewPath !== path) return;
-
-    if (arrayBuffer.byteLength > PREVIEW_MAX_BYTES) {
-      if (previewContent) previewContent.innerHTML = `<div class="text-slate-400 text-sm text-center p-6"><i class="fa-solid fa-file mr-2"></i>File too large to preview (${escapeHtml(formatBytes(arrayBuffer.byteLength))})</div>`;
-      if (previewStatusEl) previewStatusEl.textContent = "";
-      return;
-    }
-
-    if (currentPreviewBlobUrl) {
-      URL.revokeObjectURL(currentPreviewBlobUrl);
-      currentPreviewBlobUrl = null;
-    }
-
-    const blob = new Blob([arrayBuffer], { type: mimeType });
-    currentPreviewBlobUrl = URL.createObjectURL(blob);
-
-    if (previewContent) {
-      previewContent.innerHTML = "";
-      if (PREVIEW_IMAGE_EXTS.has(getFileExt(fileName))) {
-        const img = document.createElement("img");
-        img.src = currentPreviewBlobUrl;
-        img.alt = "";
-        previewContent.appendChild(img);
-      } else {
-        const obj = document.createElement("object");
-        obj.data = currentPreviewBlobUrl;
-        obj.type = "application/pdf";
-        previewContent.appendChild(obj);
-      }
-    }
-
-    if (previewStatusEl) previewStatusEl.textContent = "";
-  } catch (err) {
-    if (currentPreviewPath !== path) return;
-    if (previewContent) previewContent.innerHTML = `<div class="text-red-400 text-sm text-center p-6"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(err.message || "Failed to load preview")}</div>`;
-    if (previewStatusEl) previewStatusEl.textContent = "";
-  }
-}
+const filePreviewModalManager = createFilePreviewModal({
+  clientId,
+  notifyToast,
+  onDownload: (path) => downloadFile(path),
+});
+let openFilePreview = filePreviewModalManager.openFilePreview;
+const transferPanelManager = createTransferPanel({
+  onCancel: (transferId) => cancelTransfer(transferId),
+});
+const {
+  addTransferToUI,
+  updateTransferProgress,
+} = transferPanelManager;
 
 const FILE_ICON_MAP = {
   // Images
@@ -1316,36 +1170,6 @@ function requestFolderAccess(path) {
   notifyToast("Asking the Mac to open Privacy settings...", "info", 3500);
 }
 
-function shouldShowParentDirectory(path) {
-  if (!path || path === ".") {
-    return false;
-  }
-
-  return true;
-}
-
-function getParentPath(path) {
-  const normalized = path.replace(/\\/g, "/");
-  const parts = normalized.split("/").filter((p) => p);
-
-  if (parts.length === 1 && parts[0].match(/^[A-Za-z]:$/)) {
-    return ".";
-  }
-
-  if (parts.length <= 1) {
-    return ".";
-  }
-
-  parts.pop();
-  let parentPath = parts.join("/");
-
-  if (parentPath.match(/^[A-Za-z]:?$/)) {
-    return parentPath.replace(/^([A-Za-z]):?$/, "$1:\\");
-  }
-
-  return parentPath || ".";
-}
-
 function createParentRow(parentPath) {
   const row = document.createElement("div");
   row.className =
@@ -2359,30 +2183,6 @@ function hideContextMenu() {
   contextMenu.classList.remove("show");
 }
 
-function formatBytes(bytes) {
-  if (bytes === 0 || bytes === 0n) return "0 B";
-  const sizes = ["B", "KB", "MB", "GB", "TB"];
-  if (typeof bytes === "bigint") {
-    const k = 1024n;
-    let i = 0;
-    let value = bytes;
-    while (value >= k && i < sizes.length - 1) {
-      value /= k;
-      i += 1;
-    }
-    return `${value.toString()} ${sizes[i]}`;
-  }
-  const k = 1024;
-  const i = Math.floor(Math.log(bytes) / Math.log(k));
-  return Math.round((bytes / Math.pow(k, i)) * 100) / 100 + " " + sizes[i];
-}
-
-function escapeHtml(text) {
-  const div = document.createElement("div");
-  div.textContent = text;
-  return div.innerHTML;
-}
-
 refreshBtn.onclick = () => listFiles(currentPath);
 
 uploadBtn.onclick = () => fileInput.click();
@@ -2686,6 +2486,7 @@ const WS_UPLOAD_MAX_TOTAL = 8 * 1024 * 1024;
 const WS_UPLOAD_CHUNK_SIZE = 512 * 1024;
 const WS_UPLOAD_CONCURRENCY = 4;
 const WS_UPLOAD_ACK_TIMEOUT_MS = 90 * 1000;
+const PREFER_HTTP_UPLOAD_PULL = true;
 
 async function uploadFileViaWsChunks(file, path, transfer) {
   const total = file.size;
@@ -2787,16 +2588,41 @@ async function uploadFile(file) {
   activeTransfers.set(transferId, transfer);
   addTransferToUI(transfer);
 
-  const useWs = file.size <= WS_UPLOAD_MAX_TOTAL;
-
   try {
-    if (useWs) {
+    if (PREFER_HTTP_UPLOAD_PULL) {
+      await uploadFileViaHttpPull(file, path, transfer);
+    } else if (file.size <= WS_UPLOAD_MAX_TOTAL) {
       await uploadFileViaWsChunks(file, path, transfer);
     } else {
       await uploadFileViaHttpPull(file, path, transfer);
     }
     finishUpload(transfer);
   } catch (err) {
+    const canFallbackToWs = PREFER_HTTP_UPLOAD_PULL && file.size <= WS_UPLOAD_MAX_TOTAL && !transfer.cancelled;
+    if (canFallbackToWs) {
+      console.warn("[filebrowser] http upload failed, falling back to ws chunks", err);
+      notifyToast("HTTP upload failed; retrying through WebSocket...", "warning", 3500);
+      transfer.sent = 0;
+      transfer.receivedBytes = 0;
+      transfer.receivedChunks = 0;
+      transfer.expectedChunks = 0;
+      transfer.completed = false;
+      transfer.ackedOffsets.clear();
+      transfer.pendingAcks.forEach((pending) => {
+        clearTimeout(pending.timeoutId);
+        try { pending.reject(new Error("switching upload method")); } catch {}
+      });
+      transfer.pendingAcks.clear();
+      transfer.progress = 0;
+      updateTransferProgress(transfer.id, 0, 0, transfer.total);
+      try {
+        await uploadFileViaWsChunks(file, path, transfer);
+        finishUpload(transfer);
+        return;
+      } catch (fallbackErr) {
+        err = fallbackErr;
+      }
+    }
     console.error("Upload error:", err);
     removeTransfer(transferId);
     fileUploads.delete(path);
@@ -2961,17 +2787,20 @@ const previewThumbBox = document.getElementById("preview-thumb-box");
 const previewNameEl = document.getElementById("preview-name");
 const previewPathEl = document.getElementById("preview-path");
 const previewMetaList = document.getElementById("preview-meta-list");
-const previewTextHeadHost = document.getElementById("preview-text-head-host");
-const previewTextHead = document.getElementById("preview-text-head");
-const previewHexBtn = document.getElementById("preview-hex-btn");
-const previewHashBtn = document.getElementById("preview-hash-btn");
-const previewHashResult = document.getElementById("preview-hash-result");
-const previewHashValue = document.getElementById("preview-hash-value");
-const previewHashKnown = document.getElementById("preview-hash-known");
 
 let currentPreviewEntry = null;
-let lastPeekCommandId = null;
-let lastHashCommandId = null;
+const fileHexHashManager = createFileHexHashManager({
+  send,
+  notifyToast,
+  getCurrentPreviewEntry: () => currentPreviewEntry,
+});
+const {
+  handleFileHashResult,
+  handleFilePeekResult,
+  openHexViewer,
+  requestFileHash,
+  requestFilePeek,
+} = fileHexHashManager;
 
 function setPreviewPaneVisible(visible) {
   if (!previewPaneHost) return;
@@ -3000,9 +2829,8 @@ function clearPreviewPane() {
   previewActiveEl?.classList.add("hidden");
   if (previewThumbBox) previewThumbBox.innerHTML = "";
   if (previewMetaList) previewMetaList.innerHTML = "";
-  if (previewTextHead) previewTextHead.textContent = "";
-  previewTextHeadHost?.classList.add("hidden");
-  previewHashResult?.classList.add("hidden");
+  fileHexHashManager.resetPreviewTextHead();
+  fileHexHashManager.resetPreviewHash();
 }
 
 function renderPreviewMeta(entry) {
@@ -3054,8 +2882,7 @@ function showPreviewForEntry(entry) {
   }
 
   // Text head — only for likely-text files under 4KB peek window
-  previewTextHeadHost?.classList.add("hidden");
-  if (previewTextHead) previewTextHead.textContent = "";
+  fileHexHashManager.resetPreviewTextHead();
   if (!entry.isDir) {
     const ext = getFileExt(entry.name);
     if (!KNOWN_BINARY_EXTS.has(ext) && !PREVIEW_IMAGE_EXTS.has(ext) && !PREVIEW_PDF_EXTS.has(ext)) {
@@ -3063,236 +2890,9 @@ function showPreviewForEntry(entry) {
     }
   }
 
-  previewHashResult?.classList.add("hidden");
-  if (previewHashValue) previewHashValue.textContent = "";
-  if (previewHashKnown) {
-    previewHashKnown.classList.add("hidden");
-    previewHashKnown.textContent = "";
-  }
+  fileHexHashManager.resetPreviewHash();
 }
 
-// ── file_peek (hex viewer + text head) ──────────────────────────────────────
-const hexViewerModal = document.getElementById("hex-viewer-modal");
-const hexViewerFile = document.getElementById("hex-viewer-file");
-const hexViewerBody = document.getElementById("hex-viewer-body");
-const hexViewerInfo = document.getElementById("hex-viewer-info");
-const hexViewerCloseBtn = document.getElementById("hex-viewer-close-btn");
-const hexViewerCopyBtn = document.getElementById("hex-viewer-copy-btn");
-
-// commandId -> { kind: 'preview'|'hex', path, fileName }
-const peekRequests = new Map();
-let lastHexBytes = null;
-let lastHexFileName = "";
-
-function requestFilePeek(path, kind) {
-  const commandId = `peek-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
-  const fileName = path.split(/[\/\\]/).pop() || "";
-  peekRequests.set(commandId, { kind, path, fileName });
-  lastPeekCommandId = commandId;
-  send({
-    type: "command",
-    commandType: "file_peek",
-    id: commandId,
-    payload: { path, bytes: 4096 },
-  });
-}
-
-function openHexViewer(path) {
-  if (!hexViewerModal) return;
-  const fileName = path.split(/[\/\\]/).pop() || "";
-  if (hexViewerFile) hexViewerFile.textContent = fileName;
-  if (hexViewerBody) hexViewerBody.innerHTML = '<div class="text-slate-400"><i class="fa-solid fa-circle-notch fa-spin mr-2"></i>Loading...</div>';
-  if (hexViewerInfo) hexViewerInfo.textContent = "";
-  hexViewerModal.classList.add("show");
-  requestFilePeek(path, "hex");
-}
-
-function closeHexViewer() {
-  hexViewerModal?.classList.remove("show");
-}
-
-function decodeTextHead(bytes) {
-  // Try UTF-8 first; fall back to latin1.
-  try {
-    return new TextDecoder("utf-8", { fatal: false }).decode(bytes);
-  } catch {
-    return new TextDecoder("latin1").decode(bytes);
-  }
-}
-
-function renderHexDump(bytes, totalSize) {
-  if (!hexViewerBody) return;
-  const len = bytes.length;
-  const rows = [];
-  for (let off = 0; off < len; off += 16) {
-    const chunk = bytes.slice(off, Math.min(off + 16, len));
-    const hexParts = [];
-    const asciiParts = [];
-    for (let i = 0; i < 16; i++) {
-      if (i < chunk.length) {
-        hexParts.push(chunk[i].toString(16).padStart(2, "0"));
-        const b = chunk[i];
-        if (b >= 0x20 && b <= 0x7e) {
-          asciiParts.push(`<span>${escapeHtml(String.fromCharCode(b))}</span>`);
-        } else {
-          asciiParts.push('<span class="np">.</span>');
-        }
-      } else {
-        hexParts.push("  ");
-        asciiParts.push(" ");
-      }
-      if (i === 7) hexParts.push("");
-    }
-    rows.push(
-      `<div class="hex-row">` +
-        `<span class="hex-off">${off.toString(16).padStart(8, "0")}</span>` +
-        `<span class="hex-bytes">${hexParts.join(" ")}</span>` +
-        `<span class="hex-ascii">${asciiParts.join("")}</span>` +
-      `</div>`
-    );
-  }
-  hexViewerBody.innerHTML = rows.join("");
-  if (hexViewerInfo) {
-    const peekStr = `${formatBytes(len)} peek`;
-    const totalStr = totalSize > 0 ? ` of ${formatBytes(totalSize)}` : "";
-    hexViewerInfo.textContent = peekStr + totalStr;
-  }
-  lastHexBytes = bytes;
-}
-
-function handleFilePeekResult(msg) {
-  const req = msg.commandId ? peekRequests.get(msg.commandId) : null;
-  if (!req) return;
-  peekRequests.delete(msg.commandId);
-
-  if (msg.error) {
-    if (req.kind === "hex") {
-      if (hexViewerBody) hexViewerBody.innerHTML = `<div class="text-red-400 p-3"><i class="fa-solid fa-exclamation-triangle mr-2"></i>${escapeHtml(msg.error)}</div>`;
-    }
-    if (req.kind === "preview" && currentPreviewEntry && currentPreviewEntry.path === req.path) {
-      previewTextHeadHost?.classList.add("hidden");
-    }
-    return;
-  }
-
-  let data = msg.data;
-  if (!data) data = new Uint8Array(0);
-  if (!(data instanceof Uint8Array)) {
-    try { data = new Uint8Array(data); } catch { data = new Uint8Array(0); }
-  }
-
-  if (req.kind === "hex") {
-    lastHexFileName = req.fileName;
-    renderHexDump(data, Number(msg.size || 0));
-    return;
-  }
-
-  // preview kind
-  if (!currentPreviewEntry || currentPreviewEntry.path !== req.path) return;
-  if (!msg.isText || data.length === 0) {
-    previewTextHeadHost?.classList.add("hidden");
-    return;
-  }
-  const text = decodeTextHead(data);
-  if (previewTextHead) previewTextHead.textContent = text;
-  previewTextHeadHost?.classList.remove("hidden");
-}
-
-hexViewerCloseBtn?.addEventListener("click", closeHexViewer);
-hexViewerModal?.addEventListener("click", (e) => {
-  if (e.target === hexViewerModal) closeHexViewer();
-});
-document.addEventListener("keydown", (e) => {
-  if (e.key === "Escape" && hexViewerModal?.classList.contains("show")) {
-    closeHexViewer();
-  }
-});
-hexViewerCopyBtn?.addEventListener("click", async () => {
-  if (!lastHexBytes) return;
-  const hex = Array.from(lastHexBytes).map((b) => b.toString(16).padStart(2, "0")).join("");
-  try {
-    await navigator.clipboard.writeText(hex);
-    notifyToast("Hex copied to clipboard", "success", 2000);
-  } catch {
-    notifyToast("Clipboard copy failed", "error", 2500);
-  }
-});
-
-// ── file_hash + tiny known catalog ──────────────────────────────────────────
-// SHA-256 hex digests for a few well-known files (operator tip). Lowercase.
-const KNOWN_HASHES_SHA256 = {
-  // empty file
-  "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855": "Empty file (0 bytes)",
-  // example placeholders — populate over time
-};
-
-// commandId -> { path, fileName, source: 'preview'|'context' }
-const hashRequests = new Map();
-
-function requestFileHash(path, source) {
-  const commandId = `hash-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
-  const fileName = path.split(/[\/\\]/).pop() || "";
-  hashRequests.set(commandId, { path, fileName, source });
-  lastHashCommandId = commandId;
-  send({
-    type: "command",
-    commandType: "file_hash",
-    id: commandId,
-    payload: { path, algorithm: "sha256" },
-  });
-  notifyToast(`Hashing ${fileName}…`, "info", 2500);
-}
-
-function handleFileHashResult(msg) {
-  const req = msg.commandId ? hashRequests.get(msg.commandId) : null;
-  if (!req) return;
-  hashRequests.delete(msg.commandId);
-
-  if (msg.error) {
-    notifyToast(`Hash failed: ${msg.error}`, "error", 5000);
-    return;
-  }
-  const digest = (msg.digest || "").toLowerCase();
-  const known = KNOWN_HASHES_SHA256[digest];
-
-  // Update preview pane if it's showing this file
-  if (currentPreviewEntry && currentPreviewEntry.path === req.path && previewHashValue) {
-    previewHashValue.textContent = digest;
-    previewHashResult?.classList.remove("hidden");
-    if (previewHashKnown) {
-      if (known) {
-        previewHashKnown.textContent = `Known: ${known}`;
-        previewHashKnown.classList.remove("hidden");
-      } else {
-        previewHashKnown.classList.add("hidden");
-      }
-    }
-  }
-
-  const msgSuffix = known ? ` — matches known: ${known}` : "";
-  notifyToast(`SHA-256: ${digest.slice(0, 16)}…${msgSuffix}`, "success", 6000);
-  navigator.clipboard?.writeText(digest).catch(() => {});
-}
-
-previewHexBtn?.addEventListener("click", () => {
-  if (currentPreviewEntry && !currentPreviewEntry.isDir) {
-    openHexViewer(currentPreviewEntry.path);
-  }
-});
-previewHashBtn?.addEventListener("click", () => {
-  if (currentPreviewEntry && !currentPreviewEntry.isDir) {
-    requestFileHash(currentPreviewEntry.path, "preview");
-  }
-});
-previewHashValue?.addEventListener("click", async () => {
-  const v = previewHashValue.textContent || "";
-  if (!v) return;
-  try {
-    await navigator.clipboard.writeText(v);
-    notifyToast("SHA-256 copied", "success", 1500);
-  } catch {}
-});
-
 // ── Sidebar Quick Access ──
 let detectedHomePath = "";
 let detectedOS = "";
@@ -3447,75 +3047,12 @@ function highlightSidebarActive() {
 updatePinnedSidebar();
 checkFeatureAccess("file_browser", clientId).then(ok => ok && connect());
 
-function addTransferToUI(transfer) {
-  const transferItem = document.createElement("div");
-  transferItem.id = `transfer-${transfer.id}`;
-  transferItem.className =
-    "transfer-item bg-slate-800/50 border border-slate-700 rounded-lg p-3";
-
-  const icon = transfer.type === "upload" ? "fa-upload" : "fa-download";
-  const color = transfer.type === "upload" ? "text-blue-400" : "text-green-400";
-
-  transferItem.innerHTML = `
-    <div class="flex items-center justify-between mb-2">
-      <div class="flex items-center gap-2 flex-1 min-w-0">
-        <i class="fa-solid ${icon} ${color}"></i>
-        <span class="text-sm truncate transfer-name"></span>
-      </div>
-      <button class="cancel-btn text-red-400 hover:text-red-300 px-2" type="button">
-        <i class="fa-solid fa-xmark"></i>
-      </button>
-    </div>
-    <div class="progress-bar-container w-full bg-slate-700 rounded-full h-2 mb-1">
-      <div class="progress-bar bg-blue-500 h-2 rounded-full transition-all duration-300" style="width: ${transfer.progress}%"></div>
-    </div>
-    <div class="flex justify-between text-xs text-slate-400">
-      <span class="progress-text">${transfer.progress}%</span>
-      <span class="size-text">${formatBytes(transfer.sent || transfer.received || 0)} / ${formatBytes(transfer.total)}</span>
-    </div>
-  `;
-
-  const nameEl = transferItem.querySelector(".transfer-name");
-  if (nameEl) {
-    nameEl.textContent = transfer.fileName;
-  }
-  const cancelBtn = transferItem.querySelector(".cancel-btn");
-  if (cancelBtn) {
-    cancelBtn.addEventListener("click", () => cancelTransfer(transfer.id));
-  }
-
-  transferList.appendChild(transferItem);
-  transferPanel.classList.remove("hidden");
-}
-
-function updateTransferProgress(transferId, progress, current, total) {
-  const transferItem = document.getElementById(`transfer-${transferId}`);
-  if (!transferItem) return;
-
-  const progressBar = transferItem.querySelector(".progress-bar");
-  const progressText = transferItem.querySelector(".progress-text");
-  const sizeText = transferItem.querySelector(".size-text");
-
-  if (progressBar) progressBar.style.width = `${progress}%`;
-  if (progressText) progressText.textContent = `${progress}%`;
-  if (sizeText)
-    sizeText.textContent = `${formatBytes(current)} / ${formatBytes(total)}`;
-}
-
 function removeTransfer(transferId) {
-  const transferItem = document.getElementById(`transfer-${transferId}`);
-  if (transferItem) {
-    transferItem.remove();
-  }
-
+  transferPanelManager.removeTransfer(transferId);
   activeTransfers.delete(transferId);
-
-  if (transferList.children.length === 0) {
-    transferPanel.classList.add("hidden");
-  }
 }
 
-window.cancelTransfer = function (transferId) {
+function cancelTransfer(transferId) {
   const transfer = activeTransfers.get(transferId);
   if (transfer) {
     transfer.cancelled = true;
@@ -3540,7 +3077,8 @@ window.cancelTransfer = function (transferId) {
 
     console.log("Transfer cancelled:", transferId);
   }
-};
+}
+window.cancelTransfer = cancelTransfer;
 
 function updateSelectionUI() {
   const count = selectedFiles.size;
@@ -3844,21 +3382,8 @@ editorSaveBtn.addEventListener("click", saveFileFromEditor);
 editorCancelBtn.addEventListener("click", closeEditor);
 editorCloseBtn.addEventListener("click", closeEditor);
 
-if (previewCloseBtn) previewCloseBtn.addEventListener("click", closePreview);
-if (previewDownloadBtn) previewDownloadBtn.addEventListener("click", () => {
-  if (currentPreviewPath) downloadFile(currentPreviewPath);
-});
-if (filePreviewModal) {
-  // Close on backdrop click.
-  filePreviewModal.addEventListener("click", (e) => {
-    if (e.target === filePreviewModal) closePreview();
-  });
-}
-document.addEventListener("keydown", (e) => {
-  if (e.key === "Escape" && filePreviewModal && filePreviewModal.classList.contains("show")) {
-    closePreview();
-  }
-});
+filePreviewModalManager.bindControls();
+fileHexHashManager.bindControls();
 
 const editorRunBtn = document.getElementById("editor-run-btn");
 editorRunBtn.addEventListener("click", () => {
diff --git a/Overlord-Server/src/server/file-transfer-state.ts b/Overlord-Server/src/server/file-transfer-state.ts
index 945e1fe..8d10214 100644
--- a/Overlord-Server/src/server/file-transfer-state.ts
+++ b/Overlord-Server/src/server/file-transfer-state.ts
@@ -202,6 +202,45 @@ export function streamFileAndDelete(tmpPath: string): ReadableStream<Uint8Array>
   });
 }
 
+export function streamFileRangeWithCleanup(
+  tmpPath: string,
+  start: number,
+  endInclusive: number,
+  cleanupOnComplete: () => void | Promise<void>,
+): ReadableStream<Uint8Array> {
+  let cancelled = false;
+  return new ReadableStream<Uint8Array>({
+    async start(controller) {
+      let fh: FileHandle | null = null;
+      try {
+        fh = await fs.open(tmpPath, "r");
+        let pos = start;
+        const READ_CHUNK = 256 * 1024;
+        while (!cancelled && pos <= endInclusive) {
+          const remaining = endInclusive - pos + 1;
+          const buf = new Uint8Array(Math.min(remaining, READ_CHUNK));
+          const { bytesRead } = await fh.read(buf, 0, buf.length, pos);
+          if (bytesRead === 0) break;
+          controller.enqueue(bytesRead === buf.length ? buf : buf.subarray(0, bytesRead));
+          pos += bytesRead;
+        }
+        if (cancelled) return;
+        await cleanupOnComplete();
+        controller.close();
+      } catch (err) {
+        try { controller.error(err); } catch {}
+      } finally {
+        if (fh) {
+          try { await fh.close(); } catch {}
+        }
+      }
+    },
+    cancel() {
+      cancelled = true;
+    },
+  });
+}
+
 export async function cleanupFileTransferTempFiles(dataDir: string): Promise<void> {
   const uploadsDir = path.join(dataDir, "uploads");
   const downloadsDir = path.join(dataDir, "downloads");
diff --git a/Overlord-Server/src/server/routes/file-download-routes.test.ts b/Overlord-Server/src/server/routes/file-download-routes.test.ts
index 2e7290b..2c55852 100644
--- a/Overlord-Server/src/server/routes/file-download-routes.test.ts
+++ b/Overlord-Server/src/server/routes/file-download-routes.test.ts
@@ -254,6 +254,126 @@ describe("file upload route flow", () => {
       await removeTempDataDir(dataDir);
     }
   });
+
+  test("keeps staged upload payload available for agent range retry after interrupted pull", async () => {
+    const auth = await createAdminToken();
+    const clientId = `client-${Date.now().toString(36)}`;
+    const dataDir = await createTempDataDir();
+    const deps = makeRouteDeps(dataDir);
+    const payload = new Uint8Array(1024 * 1024 + 17);
+    crypto.getRandomValues(payload.subarray(0, Math.min(payload.length, 65536)));
+
+    clientManager.addClient(clientId, {
+      id: clientId,
+      lastSeen: Date.now(),
+      role: "client",
+      ws: { send: () => {} },
+    });
+
+    const prevDisableAgentAuth = process.env.OVERLORD_DISABLE_AGENT_AUTH;
+    process.env.OVERLORD_DISABLE_AGENT_AUTH = "true";
+
+    try {
+      const requestUrl = new URL("https://localhost/api/file/upload/request");
+      const requestRes = await handleFileDownloadRoutes(
+        new Request(requestUrl, {
+          method: "POST",
+          headers: {
+            "Content-Type": "application/json",
+            Authorization: `Bearer ${auth.token}`,
+          },
+          body: JSON.stringify({
+            clientId,
+            path: "C:\\Games\\retry.bin",
+            fileName: "retry.bin",
+          }),
+        }),
+        requestUrl,
+        mockServer,
+        deps,
+      );
+      const requestJson = await requestRes!.json() as any;
+
+      const stageUrl = new URL(`https://localhost${requestJson.uploadUrl}`);
+      const stageRes = await handleFileDownloadRoutes(
+        new Request(stageUrl, {
+          method: "POST",
+          headers: {
+            "Content-Type": "application/octet-stream",
+            Authorization: `Bearer ${auth.token}`,
+          },
+          body: payload,
+        }),
+        stageUrl,
+        mockServer,
+        deps,
+      );
+      const stageJson = await stageRes!.json() as any;
+      const pullUrl = new URL(stageJson.pullUrl);
+
+      const firstPullRes = await handleFileDownloadRoutes(
+        new Request(pullUrl, {
+          method: "GET",
+          headers: { "x-overlord-client-id": clientId },
+        }),
+        pullUrl,
+        mockServer,
+        deps,
+      );
+      expect(firstPullRes).not.toBeNull();
+      expect(firstPullRes!.status).toBe(200);
+      const reader = firstPullRes!.body!.getReader();
+      const firstRead = await reader.read();
+      expect(firstRead.done).toBe(false);
+      const firstChunk = firstRead.value!;
+      expect(firstChunk.byteLength).toBeGreaterThan(0);
+      await reader.cancel();
+
+      const retryStart = firstChunk.byteLength;
+      const retryRes = await handleFileDownloadRoutes(
+        new Request(pullUrl, {
+          method: "GET",
+          headers: {
+            "x-overlord-client-id": clientId,
+            Range: `bytes=${retryStart}-`,
+          },
+        }),
+        pullUrl,
+        mockServer,
+        deps,
+      );
+      expect(retryRes).not.toBeNull();
+      expect(retryRes!.status).toBe(206);
+      expect(retryRes!.headers.get("Content-Range")).toBe(
+        `bytes ${retryStart}-${payload.length - 1}/${payload.length}`,
+      );
+      const retried = new Uint8Array(await retryRes!.arrayBuffer());
+      expect(retried.length).toBe(payload.length - retryStart);
+      expect(retried[0]).toBe(payload[retryStart]);
+      expect(retried[retried.length - 1]).toBe(payload[payload.length - 1]);
+
+      const pullAgainRes = await handleFileDownloadRoutes(
+        new Request(pullUrl, {
+          method: "GET",
+          headers: { "x-overlord-client-id": clientId },
+        }),
+        pullUrl,
+        mockServer,
+        deps,
+      );
+      expect(pullAgainRes).not.toBeNull();
+      expect(pullAgainRes!.status).toBe(404);
+    } finally {
+      if (prevDisableAgentAuth === undefined) {
+        delete process.env.OVERLORD_DISABLE_AGENT_AUTH;
+      } else {
+        process.env.OVERLORD_DISABLE_AGENT_AUTH = prevDisableAgentAuth;
+      }
+      clientManager.deleteClient(clientId);
+      deleteUser(auth.userId);
+      await removeTempDataDir(dataDir);
+    }
+  });
 });
 
 async function createOperatorToken(opts: { fileBrowserAllowed: boolean; clientScope?: "none" | "all" } = { fileBrowserAllowed: true, clientScope: "all" }) {
diff --git a/Overlord-Server/src/server/routes/file-download-routes.ts b/Overlord-Server/src/server/routes/file-download-routes.ts
index 14ef91b..7e72f94 100644
--- a/Overlord-Server/src/server/routes/file-download-routes.ts
+++ b/Overlord-Server/src/server/routes/file-download-routes.ts
@@ -16,7 +16,7 @@ import {
   isSafeRemotePath,
   makeIncrementalPullStream,
   notifyPullWaiters,
-  streamFileAndDelete,
+  streamFileRangeWithCleanup,
   uploadIntents,
   uploadPulls,
   waitForPullProgress,
@@ -557,15 +557,21 @@ export async function handleFileDownloadRoutes(
     };
 
     if (pull.deleteFile) {
-      uploadPulls.delete(pullId);
-      clearTimeout(pull.timeout);
+      const cleanupPull = async () => {
+        const current = uploadPulls.get(pullId);
+        if (current === pull) {
+          uploadPulls.delete(pullId);
+          clearTimeout(pull.timeout);
+        }
+        await fs.unlink(pull.tmpPath).catch(() => {});
+      };
 
       if (pull.state && !rangeHeader) {
         const expected = pull.expectedTotal ?? pull.size;
         const stream = makeIncrementalPullStream(pull);
         const cleanupOnDone = stream.pipeThrough(new TransformStream({
           flush: async () => {
-            await fs.unlink(pull.tmpPath).catch(() => {});
+            await cleanupPull();
           },
         }));
         return new Response(cleanupOnDone, {
@@ -578,13 +584,53 @@ export async function handleFileDownloadRoutes(
           await waitForPullProgress(pull.state);
         }
         if (pull.state.error) {
-          await fs.unlink(pull.tmpPath).catch(() => {});
+          await cleanupPull();
           return new Response("Upload streaming failed", { status: 500 });
         }
       }
-      return new Response(streamFileAndDelete(pull.tmpPath), {
-        headers: { ...baseHeaders, "Content-Length": String(pull.size) },
-      });
+
+      if (rangeHeader) {
+        const match = /^bytes=(\d+)-(\d*)$/.exec(rangeHeader.trim());
+        if (!match) {
+          return new Response("Range Not Satisfiable", {
+            status: 416,
+            headers: { ...baseHeaders, "Content-Range": `bytes */${pull.size}` },
+          });
+        }
+        const start = Number(match[1]);
+        const end = match[2] === "" ? pull.size - 1 : Number(match[2]);
+        if (
+          !Number.isFinite(start) ||
+          !Number.isFinite(end) ||
+          start < 0 ||
+          end >= pull.size ||
+          start > end
+        ) {
+          return new Response("Range Not Satisfiable", {
+            status: 416,
+            headers: { ...baseHeaders, "Content-Range": `bytes */${pull.size}` },
+          });
+        }
+        const length = end - start + 1;
+        return new Response(
+          streamFileRangeWithCleanup(pull.tmpPath, start, end, cleanupPull),
+          {
+            status: 206,
+            headers: {
+              ...baseHeaders,
+              "Content-Range": `bytes ${start}-${end}/${pull.size}`,
+              "Content-Length": String(length),
+            },
+          },
+        );
+      }
+
+      return new Response(
+        streamFileRangeWithCleanup(pull.tmpPath, 0, Math.max(0, pull.size - 1), cleanupPull),
+        {
+          headers: { ...baseHeaders, "Content-Length": String(pull.size) },
+        },
+      );
     }
 
     if (rangeHeader) {