docs: add JSDoc headers to entry points and key modules

Add @fileoverview documentation to:
- src/index.ts - CLI entry point
- src/cli.ts - Command definitions
- src/templates/claude-md.ts - Template generation with function docs
- src/web/server.ts - Web server and API

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

src/index.ts

@@ -1,4 +1,12 @@
 #!/usr/bin/env node
+/**
+ * @fileoverview Claudeman CLI entry point
+ *
+ * This is the main executable entry point for the Claudeman CLI.
+ * It sets up global error handlers and invokes the CLI parser.
+ *
+ * @module index
+ */
 
 import { program } from './cli.js';