hermes - 💡(How to fix) Fix Kanban needs a first-class parked/manual mode so tasks can exist without gateway dispatch spawning work

Hermes Kanban currently acts as an executable queue once tasks become dispatch-eligible. That is fine for active orchestration, but it is missing a simple operator control:

• keep agents online
• keep tasks on the board
• do not let the gateway dispatcher start work

Current workaround:

kanban:
  dispatch_in_gateway: false
  auto_decompose: false

That works, but it is too coarse. It disables dispatch globally instead of letting operators park specific tasks or boards.

This matters in real use because there is a common need for:

• backlog / planning boards
• parked tasks awaiting approval
• visible assigned work that should not execute yet

Related upstream context:

• Kanban RFC: assigned ready tasks are intended to be dispatchable
  https://github.com/NousResearch/hermes-agent/issues/16102
• Dispatcher pickup semantics noted here
  https://github.com/NousResearch/hermes-agent/issues/20875
• Cross-board / cross-profile dispatch surprise
  https://github.com/NousResearch/hermes-agent/issues/21877
• Related request for non-auto-spawn lanes
  https://github.com/NousResearch/hermes-agent/issues/20157

Requested behavior

Hermes should support one of these first-class models:

1. A non-dispatchable task status such as parked / manual / hold
2. A per-task flag like dispatch_enabled: false
3. A board-level manual mode where tasks are visible but never auto-claimed
4. An approval gate before first claim/spawn

Acceptance criteria

1. A task can stay on the board without being auto-spawned.
2. Assignment alone does not make a task runnable when it is explicitly parked/manual.
3. The dashboard and CLI make the non-runnable state obvious.
4. The operator can later promote the task/board into runnable state explicitly.

Right now the only reliable way to get this behavior is to disable gateway dispatch globally. That is a missing control-plane feature, not just a UX issue.