feat: edit and remove queued messages

[danielkov]

Summary

Add TUI controls to edit or remove pending injected messages without changing delivered transcript history. Edits preserve the message ID and queue position.

Technical details

Pending-message controls

F2 focuses the queue, arrow keys select a message, Enter opens the editor, and Backspace/Delete requests removal. Empty queues do not capture focus, and the selector closes automatically when the last pending message disappears. After asynchronous closure, stale send/delete keys cannot touch the parked draft until typing, pasting, cursor movement, or Esc acknowledges composer focus; normal typing remains responsive. Saving or cancelling restores the parked composer draft and attachments; newer edits survive late responses.

Mutations run asynchronously with session-generation and request/edit-token checks, keeping rendering and global shortcuts responsive during delivery races. Editing requires session.inject.pending.replace. Messages containing media remain sendable and removable, but the text-only queue editor refuses to edit them rather than discard attachments.

AgentKit integration

Wire session/replace_inject into Kit's ACP v2 server and repin agentkit-acp and agentkit-loop to AgentKit commit 8e4ee26 on feat/acp-v2-session-inject. That commit adds atomic replacement, capability advertisement, content validation, and delivery-race handling. The reviewed pin delta changes no registry packages, dependency versions, or enabled features.

[kit-code-agent]

Queue focus can prevent bracketed paste from reaching the session rename field when the asynchronous session picker opens after F2.

[kit-code-agent]

No issues found. The changes look good to merge.

[kit-code-agent]

Automatic queue closure can reinterpret a queue Enter or Backspace as submission or deletion of the parked composer draft.

[kit-code-agent]

No issues found. The changes look good to merge.