docs(6206): settings, projects, api routes and three models drop citations; four capitalised services stragglers

- api.py's build-version docstring states why a channel name is not a build
  id, without the dated incident.
- rule_version states why rules need a history, without the rule that was
  rescoped and the date.
- Capitalised "Rule N" / "Milestone N" citations the earlier lowercase grep
  missed, in reply_shapes, supersession, services/family and models/family.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/scribe/services/supersession.py

@@ -82,7 +82,7 @@ async def set_supersedes(
     silent drop, because it is the one case where the caller might reasonably
     believe they succeeded and be wrong in a way that matters — demoting someone
     else's record out of their retrieval is damage you cannot see from the
-    outside. Rule #47.
+    outside.
     """
     if not await access.can_write_note(user_id, note_id):
         return None