- Add attachment-first chat compose flow with paperclip picker, drag-and-drop, and paste support in ChatView input
- Render pending attachment preview chips with per-file remove actions and drag-over visual affordance
- Display sent message attachments with image/file presentation and accessible focus/interaction styling
- Update ChatView tests and icon mocks to cover attachment-only sends, file selection, and preview behavior
Fusion-Task-Id: FN-2911
d155b8964a