Use asyncio.run in sync tests that were relying on an implicit current event loop. This makes the gateway send-image and Slack connect tests pass reliably under Python 3.11+ and xdist workers.
Fallback paths in send_image_file, send_video, and send_document called
super() without metadata, causing replies to appear outside the thread
when file upload fails. Use self.send() with metadata instead to preserve
thread_ts context.
- Increase MAX_MESSAGE_LENGTH from 3,900 to 39,000 (Slack API allows 40k)
- Implement real typing indicator using assistant.threads.setStatus API
- Shows 'BotName is thinking...' next to the bot name in threads
- Auto-clears when the bot sends a reply
- Requires assistant:write or chat:write scope
- Falls back silently if scope unavailable (reactions still work)
- 4 new tests for typing indicator
- Register no-op app_mention event handler to suppress Bolt 404 errors.
The 'message' handler already processes @mentions in channels, so
app_mention is acknowledged without duplicate processing.
- Add send_document() for native file attachments (PDFs, CSVs, etc.)
via files_upload_v2, matching the pattern from Telegram PR #779.
- Add send_video() for native video uploads via files_upload_v2.
- Handle incoming document attachments from users: download, cache,
and inject text content for .txt/.md files (capped at 100KB),
following the same pattern as the Telegram adapter.
- Add _download_slack_file_bytes() helper for raw byte downloads.
- Add 24 new tests covering all new functionality.
Fixes the unhandled app_mention events reported in gateway logs.
