Fix dev server hang (broken dev script + IPv6 proxy stall)

`pnpm dev` never started the backend: the server dev script ran
`node --experimental-strip-types src/index.ts`, but type-stripping doesn't
rewrite the `.js` import specifiers to `.ts`, so it crashed on
ERR_MODULE_NOT_FOUND. With no backend on :3000, the Vite proxy waited the full
timeout on every /api call — the "Loading…" and "Signing in…" hangs.

- server dev script -> `tsx watch` (resolves .js->.ts, has built-in watch).
- Vite proxy targets 127.0.0.1 (not "localhost") so it never tries IPv6 ::1
  first and stall — the backend binds IPv4. Belt-and-suspenders for the same
  hang, notably under WSL2 mirrored networking.

Verified: pnpm dev boots the backend; health/auth/me ~5ms; browser login is
instant (was minutes).

apps/server/package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "build": "tsc -b",
-    "dev": "node --env-file-if-exists=.env --watch --experimental-strip-types src/index.ts",
+    "dev": "tsx watch --env-file-if-exists=.env src/index.ts",
     "start": "node --env-file-if-exists=.env dist/index.js",
     "seed-admin": "node --env-file-if-exists=.env scripts/seed-admin.mjs",
     "typecheck": "tsc --noEmit",
@@ -27,6 +27,7 @@
   "devDependencies": {
     "@types/bcrypt": "6.0.0",
     "@types/node": "25.9.3",
+    "tsx": "4.22.4",
     "typescript": "6.0.3"
   }
 }

apps/web/vite.config.ts

@@ -9,8 +9,11 @@ export default defineConfig({
   server: {
     port: 5173,
     proxy: {
-      "/api": "http://localhost:3000",
-      "/health": "http://localhost:3000",
+      // Use 127.0.0.1 (not "localhost") so the proxy never tries IPv6 ::1
+      // first and stall — the backend binds IPv4. Avoids slow/hung requests,
+      // notably under WSL2 mirrored networking.
+      "/api": "http://127.0.0.1:3000",
+      "/health": "http://127.0.0.1:3000",
     },
   },
   build: {