feat: add graceful shutdown endpoint and cli service management

- Add /shutdown endpoint for graceful server shutdown
- Add 'aha ps' command to list running services
- Add comprehensive API documentation for shutdown endpoint
- Enhance CLI with --allow-remote-shutdown flag
- Implement process management module with service discovery
- Add graceful shutdown handling for Ctrl+C signals

src/lib.rs

@@ -2,5 +2,6 @@ pub mod chat_template;
 pub mod exec;
 pub mod models;
 pub mod position_embed;
+pub mod process;
 pub mod tokenizer;
 pub mod utils;