feat(kanban): durable multi-profile collaboration board (#17805)

Salvage of PR #16100 onto current main (after emozilla's #17514 fix
that unblocks plugin Pydantic body validation). History preserved on
the standing `feat/kanban-standing` branch; this squashes the 22
iterative commits into one clean landing.

What this lands:
- SQLite kernel (hermes_cli/kanban_db.py) — durable task board with
  tasks, task_links, task_runs, task_comments, task_events,
  kanban_notify_subs tables. WAL mode, atomic claim via CAS,
  tenant-namespaced, skills JSON array per task, max-runtime timeouts,
  worker heartbeats, idempotency keys, circuit breaker on repeated
  spawn failures, crash detection via /proc/<pid>/status, run history
  preserved across attempts.
- Dispatcher — runs inside the gateway by default
  (`kanban.dispatch_in_gateway: true`). Ticks every 60s, reclaims
  stale claims, promotes ready tasks, spawns `hermes -p <assignee>
  chat -q "work kanban task <id>"` with HERMES_KANBAN_TASK +
  HERMES_KANBAN_WORKSPACE env. Auto-loads `--skills kanban-worker`
  plus any per-task skills. Health telemetry warns on stuck ready
  queue.
- Structured tool surface (tools/kanban_tools.py) — 7 tools
  (kanban_show, kanban_complete, kanban_block, kanban_heartbeat,
  kanban_comment, kanban_create, kanban_link). Gated on
  HERMES_KANBAN_TASK via check_fn so zero schema footprint in normal
  sessions.
- System-prompt guidance (agent/prompt_builder.py KANBAN_GUIDANCE)
  injected only when kanban tools are active.
- Dashboard plugin (plugins/kanban/dashboard/) — Linear-style board
  UI: triage/todo/ready/running/blocked/done columns, drag-drop,
  inline create, task drawer with markdown, comments, run history,
  dependency editor, bulk ops, lanes-by-profile grouping, WS-driven
  live refresh. Matches active dashboard theme via CSS variables.
- CLI — `hermes kanban init|create|list|show|assign|link|unlink|
  claim|comment|complete|block|unblock|archive|tail|dispatch|context|
  init|gc|watch|stats|notify|log|heartbeat|runs|assignees` +
  `/kanban` slash in-session.
- Worker + orchestrator skills (skills/devops/kanban-worker +
  kanban-orchestrator) — pattern library for good summary/metadata
  shapes, retry diagnostics, block-reason examples, fan-out patterns.
- Per-task force-loaded skills — `--skill <name>` (repeatable),
  stored as JSON, threaded through to dispatcher argv as one
  `--skills X` pair per skill alongside the built-in kanban-worker.
  Dashboard + CLI + tool parity.
- Deprecation of standalone `hermes kanban daemon` — stub exits 2
  with migration guidance; `--force` escape hatch for headless hosts.
- Docs (website/docs/user-guide/features/kanban.md + kanban-tutorial.md)
  with 11 dashboard screenshots walking through four user stories
  (Solo Dev, Fleet Farming, Role Pipeline, Circuit Breaker).
- Tests (251 passing): kernel schema + migration + CAS atomicity,
  dispatcher logic, circuit breaker, crash detection, max-runtime
  timeouts, claim lifecycle, tenant isolation, idempotency keys, per-
  task skills round-trip + validation + dispatcher argv, tool surface
  (7 tools × round-trip + error paths), dashboard REST (CRUD + bulk
  + links + warnings), gateway-embedded dispatcher (config gate, env
  override, graceful shutdown), CLI deprecation stub, migration from
  legacy schemas.

Gateway integration:
- GatewayRunner._kanban_dispatcher_watcher — new asyncio background
  task, symmetric with _kanban_notifier_watcher. Runs dispatch_once
  via asyncio.to_thread so SQLite WAL never blocks the loop. Sleeps
  in 1s slices for snappy shutdown. Respects HERMES_KANBAN_DISPATCH_IN_GATEWAY=0
  env override for debugging.
- Config: new `kanban` section in DEFAULT_CONFIG with
  `dispatch_in_gateway: true` (default) + `dispatch_interval_seconds: 60`.
  Additive — no \_config_version bump needed.

Forward-compat:
- workflow_template_id / current_step_key columns on tasks (v1 writes
  NULL; v2 will use them for routing).
- task_runs holds claim machinery (claim_lock, claim_expires,
  worker_pid, last_heartbeat_at) so multi-attempt history is first-
  class from day one.

Closes #16102.

Co-authored-by: emozilla <emozilla@nousresearch.com>

hermes_cli/config.py

@@ -1104,6 +1104,24 @@ DEFAULT_CONFIG = {
         "max_parallel_jobs": None,
     },
 
+    # Kanban multi-agent coordination — controls the dispatcher loop that
+    # spawns workers for ready tasks. The dispatcher ticks every N seconds
+    # (default 60), reclaims stale claims, promotes dependency-satisfied
+    # todos to ready, and fires `hermes -p <assignee> chat -q ...` for
+    # each claimable ready task. One dispatcher per profile is sufficient;
+    # running more than one on the same kanban.db will race for claims.
+    "kanban": {
+        # Run the dispatcher inside the gateway process. On by default —
+        # the cost is ~300µs every `dispatch_interval_seconds` when idle,
+        # and gateway is the supervisor users already have. Set to false
+        # only if you run the dispatcher as a separate systemd unit or
+        # don't want the gateway to spawn workers.
+        "dispatch_in_gateway": True,
+        # Seconds between dispatcher ticks (idle or not). Lower = snappier
+        # pickup of newly-ready tasks; higher = less SQL pressure.
+        "dispatch_interval_seconds": 60,
+    },
+
     # execute_code settings — controls the tool used for programmatic tool calls.
     "code_execution": {
         # Execution mode: