1ab6f34791
- Drop empty entries before validating SLACK_ALLOWED_USERS so a trailing or interior comma (which the gateway silently tolerates in gateway/platforms/slack.py) is no longer rejected at the dashboard. - Hoist the member-ID regex to a module-level _SLACK_MEMBER_ID_RE constant and note it stays in sync with the frontend SLACK_MEMBER_ID_RE. - Add a regression test for the trailing-comma case.