feat: add daemon skeleton with lifecycle management

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/daemon/index.ts

@@ -0,0 +1,30 @@
+import { Lifecycle } from './lifecycle.js';
+import type { Config } from '../config/index.js';
+
+export interface DaemonContext {
+  config: Config;
+  lifecycle: Lifecycle;
+}
+
+export async function startDaemon(config: Config): Promise<DaemonContext> {
+  const lifecycle = new Lifecycle();
+
+  // Register signal handlers
+  const signalHandler = () => {
+    lifecycle.shutdown().then(() => process.exit(0));
+  };
+
+  process.on('SIGINT', signalHandler);
+  process.on('SIGTERM', signalHandler);
+
+  lifecycle.onShutdown(async () => {
+    process.off('SIGINT', signalHandler);
+    process.off('SIGTERM', signalHandler);
+  });
+
+  console.log('Flynn daemon started');
+
+  return { config, lifecycle };
+}
+
+export { Lifecycle } from './lifecycle.js';