docs(rag): rewrite the KB docs to the real gateway verb surface

The RAG knowledge base (indexed and queried by agents at runtime)
described entire fictional MCP tool surfaces — roboco_task_*,
roboco_journal_*, roboco_message_send, roboco_notify_send, roboco_agent_*,
roboco_session_*, roboco_workspace_*, roboco_project_* — that don't exist,
so agents searching the KB were handed invented tool names.

Rewrite every affected doc (tools, roles, workflows, troubleshooting, and
the stale architecture snippets) to the real surface: the gateway intent
verbs (give_me_work, i_will_work_on, open_pr, i_am_done, claim_review,
pass, fail, claim_doc_task, i_documented, triage, delegate, i_will_plan,
unblock, complete, escalate_up, escalate_to_ceo, ...) and content tools
(commit, note(scope=...), say, dm, evidence, notify*, open_session,
channels). Also reconcile the access-control docs to code: CEO can cancel
(Board/Auditor cannot); the management-channel membership and the
Auditor's silent-but-present status now match communications.py.

docs/rag/README.md

@@ -28,4 +28,4 @@ When searching the knowledge base:
 - Use `roboco_rag_query()` for AI-synthesized answers
 - Use `roboco_ask_mentor()` for conversational help
 
-See `/docs/workflows/KNOWLEDGE_BASE.md` for full KB tool reference.
+See `docs/rag/tools/kb-tools.md` for the full KB tool reference.