feat: board-level kanban notification subscriptions (ADR-0011)

[KulltivateAI]

Summary

Implements board-level notification subscriptions per ADR-0011. Users can subscribe to ALL events on a kanban board (not just per-task), with optional kind filtering.

Changes (3 files, +223/-32)

hermes_cli/kanban_db.py — DB layer

• Added BOARD_SUB_TASK_ID = '__board__' constant
• Schema migration: kinds TEXT column on kanban_notify_subs (idempotent ALTER TABLE)
• add_notify_sub(): accepts optional kinds parameter
• list_notify_subs(): new board_only kwarg to filter board-level subs
• New claim_unseen_board_events(): queries global task_events table with CAS cursor pattern, LIMIT 200

hermes_cli/kanban.py — CLI

• notify-subscribe: --board flag (mutually exclusive with task_id), --kinds flag
• notify-unsubscribe: --board flag support
• notify-list: shows [BOARD] prefix for board-level subs, displays kinds filter

gateway/run.py — Watcher

• Splits subs into regular vs board-level
• Board subs processed after regular subs with dedup via delivered_event_keys set
• Board subs skip auto-unsubscribe on terminal task states

Design Decisions

• kinds stored as comma-separated TEXT (NULL = all terminal kinds) — backward compatible
• Dedup tracks (event_id, platform, chat_id, thread_id) tuples
• Board subs are permanent until explicit unsubscribe

Testing

• 4515 tests pass (4 failures are pre-existing/flaky on main, unrelated to this change)

[teknium1]

Thanks for the contribution. The feature gap is real on current main: notify-subscribe still requires a task id in hermes_cli/kanban.py:684, and the live watcher still claims per-task events at gateway/kanban_watchers.py:181.

Problems

• The watcher code in this PR targets gateway/run.py, but current main moved this loop into gateway/kanban_watchers.py:29. A salvage needs to apply the board-subscription logic there, where list_notify_subs and claim_unseen_events_for_sub are called at gateway/kanban_watchers.py:163 and gateway/kanban_watchers.py:181.
• Board notifications attach the real task at gateway/run.py:4679 in the PR, but the formatter still uses sub['task_id'] below; for a board subscription that would render the sentinel board instead of the event task id.
• The PR adds no tests. Existing notification coverage is in tests/hermes_cli/test_kanban_notify.py, tests/hermes_cli/test_kanban_core_functionality.py, and tests/gateway/test_kanban_notifier.py, and this feature needs coverage for board subscribe/list/unsubscribe, kind filters, dedup with task-level subscriptions, and permanent board subscriptions.
• Current main has kanban_notify_subs rebuild specs at hermes_cli/kanban_db.py:1855; the new kinds column needs to be included in those current-main schema paths too.

Suggested changes

• Port the watcher changes to gateway/kanban_watchers.py.
• Render board-level messages with ev.task_id/task.id instead of the board sentinel.
• Add focused DB/CLI/watcher regression tests.

Automated hermes-sweeper review.

[teknium1]

This supplies the real task object, but the message formatter below still interpolates sub['task_id']; for a board subscription that is the board sentinel, so the user-facing notification would not identify the actual task. Please render board events with ev.task_id or the loaded task id.