feat: add PTY/terminal session support to Process Manager API

Add Docker-style terminal support with -t (TTY) and -i (interactive) flags:

Backend (Rust):
- Add portable-pty dependency for PTY allocation on Unix
- Extend StartProcessRequest with tty, interactive, and terminalSize options
- Add PTY process spawning with TERM=xterm-256color
- Add WebSocket endpoint for bidirectional terminal I/O
- Add terminal resize endpoint (POST /process/:id/resize)
- Add terminal input endpoint (POST /process/:id/input)
- Support base64-encoded binary input
- Process info now includes tty, interactive, and terminalSize fields
- Terminal output is logged to combined.log for persistence

Frontend (Inspector UI):
- Add @xterm/xterm and addons for terminal rendering
- Create Terminal component with xterm.js integration
- Add tabbed view (Terminal/Logs) for PTY processes
- Terminal auto-connects via WebSocket when process is expanded
- Support terminal resize with ResizeObserver
- Show PTY badge on processes with TTY enabled
- Graceful handling of process exit and disconnection

API:
- GET /v1/process/:id/terminal - WebSocket for terminal I/O
- POST /v1/process/:id/resize - Resize terminal (cols, rows)
- POST /v1/process/:id/input - Write data to terminal

WebSocket protocol:
- type: 'data' - Terminal output (server -> client)
- type: 'input' - Terminal input (client -> server)
- type: 'resize' - Resize request (client -> server)
- type: 'exit' - Process exited (server -> client)
- type: 'error' - Error message (server -> client)

frontend/packages/inspector/package.json

@@ -21,6 +21,9 @@
   "dependencies": {
     "lucide-react": "^0.469.0",
     "react": "^18.3.1",
-    "react-dom": "^18.3.1"
+    "react-dom": "^18.3.1",
+    "@xterm/xterm": "^5.5.0",
+    "@xterm/addon-fit": "^0.10.0",
+    "@xterm/addon-web-links": "^0.11.0"
   }
 }