Expand the kanban to carry support tickets (Slack-linked, stable sync)

[rogeriochaves]

Summary

Proposal from standup: the kanban should also carry support tickets, so assignment, follow-up, and status live on one board. Direction discussed: keep the Slack-native capture (click to track, auto-links threads, agents read the threads to update status), and add a stable sync mechanism between Slack-tracked tickets and the GitHub board (labels or links) rather than an agent copying items back and forth by hand.

Acceptance criteria

• Design note: how a Slack ticket maps to a board item and back (ids, labels, status)
• Sync is idempotent and survives both sides editing
• Support items visible on the board with owner and status without manual duplication