fix(desktop): restore managed Node server startup (#348)

## Summary
- revert the Bun standalone desktop packaging path and restore the
server's original `dist/bin.js` bootstrap flow
- add a managed Node runtime for Electron and Tauri that downloads only
the current platform/arch artifact into `~/.config/codenomad`
- update desktop startup and packaging scripts so packaged apps use the
managed runtime consistently, and clean up Electron's expected
navigation-abort log noise

## Testing
- npm run typecheck --workspace @neuralnomads/codenomad-electron-app
- cargo check
- npm run build --workspace @neuralnomads/codenomad
- npm run build:mac --workspace @neuralnomads/codenomad-electron-app
- launch
`packages/electron-app/release/mac-arm64/CodeNomad.app/Contents/MacOS/CodeNomad`
and verify the packaged server reaches ready with the managed Node
runtime

packages/server/package.json

@@ -18,7 +18,6 @@
   },
   "scripts": {
     "build": "npm run build:ui && npm run prepare-ui && tsc -p tsconfig.json && node ./scripts/copy-auth-pages.mjs && npm run prepare-config",
-    "build:standalone": "node ./scripts/build-standalone.mjs",
     "build:ui": "npm run build --prefix ../ui",
     "prepare-ui": "node ./scripts/copy-ui-dist.mjs",
     "prepare-config": "node ./scripts/copy-opencode-config.mjs",
@@ -26,16 +25,16 @@
     "typecheck": "tsc --noEmit -p tsconfig.json"
   },
   "dependencies": {
-    "@fastify/cors": "^11.2.0",
-    "@fastify/reply-from": "^12.6.2",
-    "@fastify/static": "^9.1.1",
+    "@fastify/cors": "^8.5.0",
+    "@fastify/reply-from": "^9.8.0",
+    "@fastify/static": "^7.0.4",
     "commander": "^12.1.0",
-    "fastify": "^5.8.5",
+    "fastify": "^4.28.1",
     "fuzzysort": "^2.0.4",
     "node-forge": "^1.3.3",
     "openai": "^6.27.0",
     "pino": "^9.4.0",
-    "undici": "^8.1.0",
+    "undici": "^6.19.8",
     "yaml": "^2.4.2",
     "yauzl": "^2.10.0",
     "zod": "^3.23.8"
@@ -43,7 +42,6 @@
   "devDependencies": {
     "@types/node-forge": "^1.3.14",
     "@types/yauzl": "^2.10.0",
-    "bun": "^1.3.13",
     "cross-env": "^7.0.3",
     "ts-node": "^10.9.2",
     "tsx": "^4.20.6",