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/server.ts

@@ -1,18 +1,15 @@
-import { createRequestHandler } from "@react-router/node";
+import { createRequestListener } from "@react-router/node";
 import { createServer } from "node:http";
 import { setupYjsWebSocket } from "./app/lib/yjs-server.ts";
 
 const port = Number(process.env.PORT ?? 3001);
 
-const handler = createRequestHandler(
-  // @ts-expect-error - build output types
-  await import("./build/server/index.js"),
-);
-
-const server = createServer((req, res) => {
-  handler(req, res);
+const listener = createRequestListener({
+  build: () => import("./build/server/index.js") as never,
 });
 
+const server = createServer(listener);
+
 setupYjsWebSocket(server);
 
 server.listen(port, () => {