fix: quiet Slack control flow

[jakelongvu-bot]

Summary

• authorize Slack approval/slash-confirm button clicks through the same SLACK_ALLOWED_USERS, GATEWAY_ALLOWED_USERS, and paired-user store used for normal messages
• attach the GatewayRunner to the Slack adapter so paired Slack users can approve actions from buttons
• suppress Slack busy/lifecycle/status callback messages so shared channels get the final assistant reply instead of extra gateway chatter

Root Cause

Slack button interactions bypass the normal message authorization path in gateway/run.py. That meant a user who was paired/authorized for Slack messages could still fail approval-button flows, and the gateway could post implementation-status noise into shared Slack channels.

Validation

• remote clean verification using staging venv:
  • python -m py_compile gateway/platforms/slack.py gateway/run.py tests/gateway/test_slack_approval_buttons.py tests/gateway/test_busy_session_ack.py
  • python -m pytest tests/gateway/test_slack_approval_buttons.py tests/gateway/test_busy_session_ack.py -q (46 passed)
• git diff --check

[jakelongvu-bot]

Vucar staging is already patched and restarted (Hermes gateway PID 1231745). Targeted staging tests passed: tests/gateway/test_slack_approval_buttons.py tests/gateway/test_busy_session_ack.py -q -> 46 passed. @thomasdongg please review/coordinate deploy with Charles/Viet Thinh.

[teknium1]

Thanks for the Slack security and delivery-focused work. The approval-button authorization issue is already resolved on current main by commit 410cb743bf6f3a7dd0b581f927bff719338a06fa (merged through #41226): plugins/platforms/slack/adapter.py:3406-3453 delegates interactive authorization to the canonical gateway auth path, and both protected action handlers gate before state mutation (:3466-3475, :3585-3594).

Problems

• The PR's Slack adapter edits target gateway/platforms/slack.py, which has since moved to plugins/platforms/slack/adapter.py. Current wiring uses adapter.set_message_handler(self._handle_message) at gateway/run.py:7062-7069; the plugin derives the runner from that bound handler at plugins/platforms/slack/adapter.py:3418-3431.
• The quiet-control-flow objective remains distinct: current main still enables busy acknowledgements by default (gateway/run.py:5510-5513) and schedules non-filtered status callbacks (gateway/run.py:17933-17953). The generic filter suppresses only matching transient status text (gateway/run.py:440-457).

Suggested changes

• Re-scope salvage to the remaining Slack quiet-flow behavior and add current-head regression coverage for the selected busy/status policy.

Automated hermes-sweeper review.

[teknium1]

Merged via #70192 — your commit was cherry-picked/reapplied onto current main with your authorship preserved in git history: your control-flow quieting was salvaged.

Thanks for the contribution!