feat: add interactive web terminal for bot containers (#232)

* feat(terminal): add interactive web terminal for bot containers

Add WebSocket-based terminal endpoint (/container/terminal/ws) that
provides a full PTY shell session inside the bot's MCP container.
Extend the gRPC proto with pty and resize fields, implement PTY exec
on the container side using creack/pty, and add an xterm.js-based
terminal component in the frontend bot detail page.

* chore: add /mcp in .gitignore

* feat(terminal): add multi-tab support, localStorage cache, and reactivity fixes

- Support unlimited terminal tabs with add/close/switch
- Cache terminal content to localStorage via SerializeAddon for session persistence
- Use shallowReactive for tab objects to ensure status updates trigger UI reactivity
- Fix listener leak by tracking and disposing onData/onResize on reconnect
- Fix bottom clipping by using inset offsets instead of padding

go.sum

@@ -61,6 +61,8 @@ github.com/containerd/typeurl/v2 v2.2.3/go.mod h1:95ljDnPfD3bAbDJRugOiShd/DlAAsx
 github.com/containernetworking/cni v1.3.0 h1:v6EpN8RznAZj9765HhXQrtXgX+ECGebEYEmnuFjskwo=
 github.com/containernetworking/cni v1.3.0/go.mod h1:Bs8glZjjFfGPHMw6hQu82RUgEPNGEaBb9KS5KtNMnJ4=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
+github.com/creack/pty v1.1.24 h1:bJrF4RRfyJnbTJqzRLHzcGaZK1NeM5kTC9jGgovnR1s=
+github.com/creack/pty v1.1.24/go.mod h1:08sCNb52WyoAwi2QDyzUCTgcvVFhUzewun7wtTfvcwE=
 github.com/cyphar/filepath-securejoin v0.6.1 h1:5CeZ1jPXEiYt3+Z6zqprSAgSWiggmpVyciv8syjIpVE=
 github.com/cyphar/filepath-securejoin v0.6.1/go.mod h1:A8hd4EnAeyujCJRrICiOWqjS1AX0a9kM5XL+NwKoYSc=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=