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

docs/cli.md

@@ -113,11 +113,11 @@ aha run -m qwen3asr-0.6b -i "audio.wav" --weight-path /path/to/model
 
 ### serv - Start service
 
-Start HTTP service only, without downloading models. Must specify local model path via `--weight-path`.
+Start HTTP service with a model. The `--weight-path` is optional - if not specified, it defaults to `~/.aha/{model_id}`.
 
 **Syntax:**
 ```bash
-aha serv [OPTIONS] --model <MODEL> --weight-path <WEIGHT_PATH>
+aha serv [OPTIONS] --model <MODEL> [--weight-path <WEIGHT_PATH>]
 ```
 
 **Options:**
@@ -127,21 +127,69 @@ aha serv [OPTIONS] --model <MODEL> --weight-path <WEIGHT_PATH>
 | `-a, --address <ADDRESS>` | Service listen address | 127.0.0.1 |
 | `-p, --port <PORT>` | Service listen port | 10100 |
 | `-m, --model <MODEL>` | Model type (required) | - |
-| `--weight-path <WEIGHT_PATH>` | Local model weight path (required) | - |
+| `--weight-path <WEIGHT_PATH>` | Local model weight path (optional) | ~/.aha/{model_id} |
+| `--allow-remote-shutdown` | Allow remote shutdown requests (not recommended) | false |
 
 **Examples:**
 
 ```bash
+# Start service with default model path (~/.aha/{model_id})
+aha serv -m qwen3vl-2b
+
 # Start service with local model
 aha serv -m qwen3vl-2b --weight-path /path/to/model
 
 # Start with specified port
-aha serv -m qwen3vl-2b --weight-path /path/to/model -p 8080
+aha serv -m qwen3vl-2b -p 8080
 
 # Specify listen address
-aha serv -m qwen3vl-2b --weight-path /path/to/model -a 0.0.0.0
+aha serv -m qwen3vl-2b -a 0.0.0.0
+
+# Enable remote shutdown (not recommended for production)
+aha serv -m qwen3vl-2b --allow-remote-shutdown
 ```
 
+### ps - List running services
+
+List all currently running AHA services with their process IDs, ports, and status.
+
+**Syntax:**
+```bash
+aha ps [OPTIONS]
+```
+
+**Options:**
+
+| Option | Description | Default |
+|--------|-------------|---------|
+| `-c, --compact` | Compact output format (show service IDs only) | false |
+
+**Examples:**
+
+```bash
+# List all running services (table format)
+aha ps
+
+# Compact output (service IDs only)
+aha ps -c
+```
+
+**Output Format:**
+
+```
+Service ID           PID        Model                Port       Address         Status
+-------------------------------------------------------------------------------------
+56860@10100          56860      N/A                  10100      127.0.0.1       Running
+```
+
+**Fields:**
+- `Service ID`: Unique identifier in format `pid@port`
+- `PID`: Process ID
+- `Model`: Model name (N/A if not detected)
+- `Port`: Service port number
+- `Address`: Service listen address
+- `Status`: Service status (Running, Stopping, Unknown)
+
 ### download - Download model
 
 Download the specified model only, without starting the service.
@@ -254,6 +302,13 @@ After the service starts, the following API endpoints are available:
 - **Format**: OpenAI Chat Completion format
 - **Streaming Support**: No
 
+### Shutdown Endpoint
+- **Endpoint**: `POST /shutdown`
+- **Function**: Gracefully shut down the server
+- **Security**: Localhost only by default, use `--allow-remote-shutdown` flag to enable remote access (not recommended)
+- **Format**: JSON response
+
+
 ## Backward Compatibility
 
 To maintain compatibility with older versions, the following two usage methods are equivalent: