refactor(kanban): fold worker/orchestrator skills into injected guidance (#50473)

The kanban-worker and kanban-orchestrator bundled skills existed only to
be force-loaded into dispatcher-spawned workers, gated by
environments:[kanban] so they wouldn't leak into normal CLI listings.
That gating was fragile (the leak that #50443 patched) and the
--skills auto-load was already best-effort — most workers ran without it
because the bundled skill isn't present in profile-scoped skills dirs.

Remove the skills entirely and promote their load-bearing content
(workspace kinds, deliverable artifacts, created-card integrity, profile
discovery) into KANBAN_GUIDANCE, which is already injected into every
kanban worker's system prompt. Net result: every worker reliably gets
the guidance, nothing can leak into a CLI/blank-slate session, and the
gating machinery is gone.

- agent/prompt_builder.py: promote the 4 load-bearing rules into KANBAN_GUIDANCE
- hermes_cli/kanban_db.py: drop --skills kanban-worker auto-injection + _kanban_worker_skill_available probe
- hermes_cli/kanban_swarm.py: drop skills=[kanban-orchestrator] on the root card
- hermes_cli/kanban.py: drop kanban-init skill seeding; fix help text
- delete skills/devops/kanban-{worker,orchestrator}
- docs: delete the two skill pages (EN+zh), fix sidebars/catalog/kanban.md/kanban-worker-lanes.md and the video-orchestrator + codex-lane references
- tests: update spawn-argv expectations; re-bound the guidance-size guard

Supersedes the skill-leak half of #50443 (credit @helix4u for flagging the area).

tests/tools/test_kanban_tools.py

@@ -1224,8 +1224,16 @@ def test_kanban_guidance_in_worker_prompt(monkeypatch, tmp_path):
 
 
 def test_kanban_guidance_prompt_size_bounded(monkeypatch, tmp_path):
-    """Sanity: the guidance block is under 4 KB so it doesn't blow
-    up the cached prompt."""
+    """Sanity: the guidance block stays lean so it doesn't blow up the
+    cached prompt.
+
+    The ceiling guards against unbounded growth, not against any growth.
+    The block absorbed the load-bearing worker/orchestrator reference
+    details (workspace kinds, deliverable artifacts, created-card claims,
+    profile discovery) when the standalone kanban-worker / kanban-orchestrator
+    skills were removed and folded into this always-injected guidance, so the
+    ceiling is sized to fit that content with a little headroom.
+    """
     monkeypatch.setenv("HERMES_KANBAN_TASK", "t_fake")
     home = tmp_path / ".hermes"
     home.mkdir()
@@ -1234,7 +1242,7 @@ def test_kanban_guidance_prompt_size_bounded(monkeypatch, tmp_path):
     monkeypatch.setattr(_P, "home", lambda: tmp_path)
 
     from agent.prompt_builder import KANBAN_GUIDANCE
-    assert 1_500 < len(KANBAN_GUIDANCE) < 4_096, (
+    assert 1_500 < len(KANBAN_GUIDANCE) < 5_500, (
         f"KANBAN_GUIDANCE is {len(KANBAN_GUIDANCE)} chars — too short (missing?) or too long"
     )