[sweep] strip Fxxx audit-ID tokens + trim bloated comments/docstrings + add behavior-change docs

Post-audit sweep over the 135 audit-fix commits since 19a474d3:

1. Stripped every # Fxxx: audit-ID token from comments AND every Fxxx token
   from docstring openings across 211 blocks / ~626 lines. The CEO flagged
   these twice: audit-issue IDs in code confuse future devs/agents. The
   descriptive text is preserved; only the Fxxx token is removed (and bloated
   narrative blocks trimmed to 1-3 lines keeping the one non-obvious invariant).
2. Trimmed bloated comments/docstrings to the concise standard (1-3 lines).
3. Added missing behavior-change docs for the audit-fix batch: prompts/roles
   (documenter, pr_reviewer, qa), user-facing docs (api auth, websockets,
   agent-gateway, megatask, merge-model, task-lifecycle, grok, resilience,
   conventions, panel, security, troubleshooting), and the RAG corpus (cell-pm,
   main-pm, pr-reviewer, qa roles; conventions; messaging-tools; escalation;
   megatask; task-claiming workflows).

Comment/docstring/prose ONLY — zero code-line edits (verified: the diff
contains no def/class/return/if/for/await/assignment/call lines). Gates green:
ruff format + ruff check clean, mypy clean on roboco/. The only pytest failures
are the pre-existing sync_branch tracing-decision gap (B1, 250be5c2) — not
sweep-caused and tracked separately.

docs/rag/tools/messaging-tools.md

@@ -18,6 +18,8 @@ Don't invent channel slugs. Call `channels()` first if unsure:
 channels()   # -> {"writable": [...], "readable": [...]}
 ```
 
+**Active-claim required (explicit `task_id`):** when you pass an explicit `task_id`, `say` / `dm` / `note` check that you are the task's **active claimant** — not just `assigned_to`, which goes stale across a reap/handoff. A reaped or reassigned agent can no longer post to a former task; if you see `not_authorized` on a content post, re-`claim` the task first (or drop the explicit `task_id` for a general channel post).
+
 Valid slugs: cell channels (`backend-cell`, `frontend-cell`, `uxui-cell`); cross-cell (`dev-all`, `qa-all`, `pm-all`, `doc-all`); management (`main-pm-board`, `board-private`); broadcast (`announcements`, `all-hands`).
 
 ## Direct message (A2A) — `dm`
@@ -40,6 +42,8 @@ notify(target="be-dev-1", text="Task ready for you", priority="normal", task_id=
 
 `priority` is `normal | high | urgent`. `task_id` auto-injects from the active task when omitted.
 
+`notify` rejects **human-only recipients** (`prompter`, `secretary`) — they have no agent ack path, so an ack-required alert to them would sit unacked forever. The CEO is allowed (acks via the panel).
+
 ## Receiving notifications
 
 Every role with an inbox gets these (so `i_am_idle()` doesn't soft-block on unread items):