Real composer

IME-safe Enter, send/stop abort contract, OOB attachment status, suggestion chips.

    AI

    Try Enter to send, Shift+Enter for newline, use the suggestion chips, or drag a file onto the composer.

brief.txt

Stop POSTs /composer/abort (stub 204). Attachments update via OOB swaps — no fake progress timers. See docs/patterns/ai-chat.md.