## Summary
- Add a terminal transfer API for browser uploads, paste-to-terminal, agent outbox listing, and downloads.
- Add the Archibald file bubble UI with drag/drop, paste, file/folder picker, animated incoming-file notifications, and a subtle WebAudio chime after user interaction.
- Add `paf-send` for agents to expose files/directories to the web terminal, plus agent context instructions.
- Deploy transfer service/Caddy/assets support and set ttyd services to `KillMode=process` so tmux sessions survive ttyd restarts.

## Test plan
- `go test ./...`
- `bash -n scripts/deploy.sh && bash -n scripts/provision.sh && bash -n configs/paf-send && git diff --check`
- Parsed embedded `paf-transfer-script` from `configs/ttyd-index.html` and `/opt/claude-code/ttyd-index.html` with Node.
- Verified `paf-send` creates an outbox file and `/terminal/api/transfers/outbox` returns the downloadable file for the active terminal ID.
- Verified live services are active and `ttyd`/`ttyd-attach` report `KillMode=process`.