docs(6206): the remaining models, routes, mcp/tools/repos and config comments drop citations

A shipped tool docstring (mcp/tools/repos bind_repo) cited this instance's
"rule 1: dev is home"; it now says what a dev-branch project should do.
routes/knowledge, routes/tasks, routes/systems and models/retrieval_log state
the property each guards rather than the bug that once broke it.

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

src/scribe/models/forge_connection.py

@@ -6,7 +6,7 @@ from scribe.models.base import TimestampMixin, iso
 
 
 class ForgeConnection(Base, TimestampMixin):
-    """One user's read-only credential for one git forge host (#2778).
+    """One user's read-only credential for one git forge host.
 
     The keyring model: a user owns a set of connections and every server-side
     forge read for a project runs on the PROJECT OWNER's set, resolved by the