Fix planner production server + use .ts extensions everywhere

- Fix createRequestHandler → createRequestListener (@react-router/node
  removed the old API)
- Move noEmit + allowImportingTsExtensions to tsconfig.base.json so all
  packages and apps inherit them consistently
- Add explicit .ts extensions to all remaining relative imports across
  packages and apps

Verified locally: node --experimental-strip-types server.ts starts and
responds 200.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/planner/tsconfig.json

@@ -8,8 +8,6 @@
   "exclude": ["build", "node_modules", "server.ts"],
   "compilerOptions": {
     "rootDirs": [".", "./.react-router/types"],
-    "noEmit": true,
-    "allowImportingTsExtensions": true,
     "types": ["vite/client"],
     "paths": {
       "~/*": ["./app/*"]