[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.

tests/unit/services/test_git_token_decryption_log.py

@@ -1,16 +1,8 @@
-"""F053: _token_for_project must log a Fernet decryption failure with the
-project context, not swallow it silently as 'no token'.
+"""Log a Fernet decryption failure with the project slug before returning None.
 
-On an encryption-key rotation the stored PAT (encrypted with the old key) can't
-be decrypted — ``crypto.decrypt_token`` raises ``EncryptionError``. The
-crypto layer logs a generic message, but ``_token_for_project`` catches the
-``EncryptionError`` and returns ``None`` with no project context, so every
-best-effort workspace git op (push, PR, clone-with-token) silently looks like
-'this project has no token' — indistinguishable from a project that genuinely
-never set one. The operator can't tell which project is wedged by a key
-rotation. Log the failure with the project slug before returning None (the
-best-effort skip behavior is preserved — this only makes the cause
-diagnosable).
+On a key rotation the stored PAT can't be decrypted; ``_token_for_project`` must
+not mask that as a silent 'no token' — log the project slug so the cause is
+diagnosable (best-effort skip behavior preserved).
 """
 
 from __future__ import annotations