T-234: Terminal.tsx — xterm.js wrap + input/output binding + exit overlay

[mpiton]

Goal

Build src/features/terminals/Terminal.tsx: a React component wrapping a single @xterm/xterm instance. Bridges keyboard input → invokeTerminalsWrite, broadcast chunks → term.write(bytes), exit event → "session ended" overlay. Lifecycle handles xterm dispose on unmount; binds FitAddon to a parent ResizeObserver.

Add @xterm/xterm, @xterm/addon-fit, @xterm/addon-web-links via pnpm add (never edit package.json). Tree-shake to keep bundle delta < 200 KB gzipped.

Acceptance criteria

• <Terminal terminalId={id} /> renders a div with xterm mounted, no SSR (Tauri webview is always client)
• Keystrokes routed via onData(data => invokeTerminalsWrite(id, encoder.encode(data)))
• Chunk subscription: store-level listener pipes bytes_base64 → decode → term.write(...)
• terminal:exited shows a dismissible overlay "Session exited (code N)" + button to close pane
• FitAddon recomputes cols/rows on parent resize via ResizeObserver, debounced 50 ms (delegated to T-236 hook)
• Copy/paste keyboard shortcuts wired (Ctrl+Shift+C / Ctrl+Shift+V on Linux, Cmd on macOS)
• Theme: respect dark/light from existing app theme provider
• Unit tests with vitest + @testing-library/react:
  • it("should render an xterm instance after mount")
  • it("should call invokeTerminalsWrite when the user types")
  • it("should display exit overlay when terminal:exited fires")
• Snapshot test for empty mounted state
• Bundle delta tracked: pnpm build size diff documented in PR

Files to create/modify

• create src/features/terminals/Terminal.tsx
• create src/features/terminals/Terminal.test.tsx
• modify pnpm-lock.yaml via pnpm add @xterm/xterm @xterm/addon-fit @xterm/addon-web-links
• modify src/styles/ for xterm CSS import (or scoped to component)

References

• PRD.md F-003 Terminaux xterm parallèles
• ARCHI.md §11.1 buffer ring + xterm SerializeAddon (defer serialise to follow-up)
• ARCHI.md §6.5 Composants terminaux

Dependencies

Blocked by T-233.