feat(desktop): packaging (C2) : prepare-server, fetch-node, electron-builder

scripts/prepare-server.mjs : rebuild forcé shared+server (évite la non-idempotence du prepack), npm pack du daemon (tarball autonome), extraction, strip des devDependencies (dont @arboretum/shared inliné, non publié), npm install --omit=dev des deps runtime avec le bon prebuild node-pty (cross via npm_config_platform/arch). scripts/fetch-node.mjs : Node standalone épinglé (22.21.1) vérifié SHA256 -> build/node.

electron-builder.yml : dist/ en ASAR ; build/server et build/node en extraResources (hors ASAR pour les .node) ; cibles Linux (AppImage+deb), Windows (nsis+portable), macOS (dmg/zip non signé) ; publish generic -> release Gitea. Scripts dist:linux/win/mac.

Vérifié : fetch-node (Node bundlé + node:sqlite), prepare-server (structure complète), et la chaîne runtime complète (Node bundlé exécute le daemon empaqueté : handshake + session bash via node-pty OK). Le wrapping electron-builder est une étape machine.

packages/desktop/package.json

@@ -8,11 +8,17 @@
   "scripts": {
     "typecheck": "tsc -p . --noEmit",
     "build": "npm run typecheck && node esbuild.mjs",
-    "dev": "node esbuild.mjs && electron ."
+    "dev": "node esbuild.mjs && electron .",
+    "prepare:server": "node scripts/prepare-server.mjs",
+    "prepare:node": "node scripts/fetch-node.mjs",
+    "dist:linux": "npm run build && npm run prepare:server -- --platform=linux && npm run prepare:node -- --platform=linux && electron-builder --linux",
+    "dist:win": "npm run build && npm run prepare:server -- --platform=win32 && npm run prepare:node -- --platform=win32 && electron-builder --win",
+    "dist:mac": "npm run build && npm run prepare:server -- --platform=darwin && npm run prepare:node -- --platform=darwin && electron-builder --mac"
   },
   "devDependencies": {
     "@types/node": "^22.10.0",
     "electron": "^33.0.0",
+    "electron-builder": "^25.1.0",
     "esbuild": "^0.21.0",
     "typescript": "^5.7.0"
   }