use tauri for desktop

build-desktop.sh

@@ -1,7 +1,25 @@
 #!/usr/bin/env bash
 set -euo pipefail
-echo "=== Building Overlord Desktop ==="
+echo "=== Building Overlord Desktop (Tauri) ==="
 cd "$(dirname "$0")/Overlord-Desktop"
-npm install
-npm run build
-echo "=== Done ==="
+
+if ! command -v bun >/dev/null 2>&1; then
+  echo "error: bun is required (https://bun.sh)" >&2
+  exit 1
+fi
+if ! command -v cargo >/dev/null 2>&1; then
+  echo "error: rust toolchain is required (https://rustup.rs)" >&2
+  exit 1
+fi
+
+bun install
+bun run vendor
+
+case "$(uname -s)" in
+  Linux*)   bun run build:linux ;;
+  Darwin*)  bun run build:mac ;;
+  MINGW*|MSYS*|CYGWIN*) bun run build:win ;;
+  *)        bun run build ;;
+esac
+
+echo "=== Done — bundle output: Overlord-Desktop/src-tauri/target/release/bundle/ ==="