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)

Cargo.toml

@@ -36,8 +36,9 @@ tower = { version = "0.5", features = ["util"] }
 tower-http = { version = "0.5", features = ["cors", "trace"] }
 
 # Async runtime
-tokio = { version = "1.36", features = ["macros", "rt-multi-thread", "signal", "time"] }
+tokio = { version = "1.36", features = ["macros", "rt-multi-thread", "signal", "time", "io-util", "sync"] }
 tokio-stream = { version = "0.1", features = ["sync"] }
+tokio-tungstenite = "0.21"
 futures = "0.3"
 
 # HTTP client
@@ -68,6 +69,10 @@ zip = { version = "0.6", default-features = false, features = ["deflate"] }
 url = "2.5"
 regress = "0.10"
 include_dir = "0.7"
+base64 = "0.21"
+
+# PTY support
+portable-pty = "0.8"
 
 # Code generation (build deps)
 typify = "0.4"