Add standalone hook entry points for context, new, save, summary, and worker

- Implemented context-hook.ts for handling session start events.
- Created new-hook.ts for user prompt submission events.
- Developed save-hook.ts for post tool use events.
- Added summary-hook.ts for handling stop events.
- Introduced worker.ts as a standalone background process for the SDK agent.
- Each hook reads input from stdin, processes it, and handles errors gracefully.

src/bin/hooks/worker.ts

@@ -0,0 +1,14 @@
+#!/usr/bin/env bun
+
+/**
+ * Worker Entry Point
+ * Standalone background process for SDK agent
+ */
+
+import { main } from '../../sdk/worker.js';
+
+// Entry point - just call the worker main function
+main().catch((error) => {
+  console.error('[SDK Worker] Fatal error:', error);
+  process.exit(1);
+});