fix(tui): restore composer shell kill shortcut - #42366

What

Restore Ctrl+D shell termination from the TUI composer Shell tab when a global binding also recognizes the key.

Before / After

Before: The Shell tab rendered kill ctrl+d, but the key could be consumed before composer.shell.kill, so no DELETE /api/shell/:id request was sent and the background process continued running.

After: While the Shell tab is active, its configured Ctrl+D binding gets first refusal and dispatches the existing composer.shell.kill command. The server removes the shell and terminates its process group.

How

• packages/tui/src/routes/session/composer/shell-tab.tsx intercepts the configured Ctrl+D shell-kill shortcut while the Shell tab is active, then dispatches the existing command.
• packages/tui/test/cli/tui/composer-keymap.test.tsx covers a focused textarea plus the global app.exit collision and verifies the shell DELETE request.

Scope

This does not change composer focus, the shell API, or process lifecycle. The existing shell.remove path already terminates the detached process group; the bug was that the TUI never invoked it.

Testing

• bun run test test/cli/tui/composer-keymap.test.tsx from packages/tui: 3 passed
• bun typecheck from packages/tui: passed
• Push hook repository typecheck: 34 packages passed
• bun run test test/tool-shell.test.ts from packages/core: 20 passed
• Live PTY verification with termctrl against the elected OpenCode service: opened the Shell tab, pressed Ctrl+D, observed the shell disappear, and confirmed the shell API no longer returned its ID

Flow

sequenceDiagram
    participant User
    participant ShellTab
    participant Server
    participant Process

    User->>ShellTab: Press Ctrl+D
    ShellTab->>ShellTab: Dispatch composer.shell.kill
    ShellTab->>Server: DELETE /api/shell/:id
    Server->>Process: Terminate process group
    Server-->>ShellTab: shell.deleted