Fix web dev startup

apps/web/scripts/dev.ts

@@ -0,0 +1,85 @@
+type PortCheck = {
+  port: number;
+  available: boolean;
+};
+
+const DEFAULT_PORTS = [3001, 3002, 3003, 3004, 3005];
+
+const isAvailable = (port: number): PortCheck => {
+  try {
+    const probe = Bun.serve({
+      port,
+      fetch: () => new Response("ok")
+    });
+    probe.stop();
+    return { port, available: true };
+  } catch {
+    return { port, available: false };
+  }
+};
+
+const parsePort = (value: string | undefined): number | null => {
+  if (!value) {
+    return null;
+  }
+
+  const parsed = Number.parseInt(value, 10);
+  if (!Number.isFinite(parsed) || parsed <= 0) {
+    return null;
+  }
+
+  return parsed;
+};
+
+const selectPort = (): number => {
+  const requested = parsePort(Bun.env.PORT);
+
+  if (requested !== null) {
+    const check = isAvailable(requested);
+    if (!check.available) {
+      throw new Error(`Port ${requested} is already in use. Set PORT to another value.`);
+    }
+    return requested;
+  }
+
+  for (const port of DEFAULT_PORTS) {
+    if (isAvailable(port).available) {
+      return port;
+    }
+  }
+
+  throw new Error("No available port found for Next dev server.");
+};
+
+const run = async () => {
+  const port = selectPort();
+  console.log(`[web] starting Next.js dev server on port ${port}`);
+
+  const path = Bun.env.PATH ?? "";
+  const cwd = `${import.meta.dir}/..`;
+
+  const child = Bun.spawn(["next", "dev", "-p", String(port)], {
+    cwd,
+    stdin: "inherit",
+    stdout: "inherit",
+    stderr: "inherit",
+    env: {
+      ...Bun.env,
+      PATH: `${cwd}/node_modules/.bin:${path}`,
+      PORT: String(port)
+    }
+  });
+
+  const shutdown = () => {
+    child.kill();
+    process.exit(0);
+  };
+
+  process.on("SIGINT", shutdown);
+  process.on("SIGTERM", shutdown);
+
+  const code = await child.exited;
+  process.exit(code ?? 0);
+};
+
+await run();