docs(6209): snippets, rule embeddings, notes, ledger ageing and references, routes, reporting, handshake, lesson kind, request deadlines, contract-around-change, family models

Twelve more test files drop issue, milestone, rule, note, lesson and
snippet numbers and the dated or one-project figures that recorded how
each property was found; the docstrings state the property and why it
holds. The contract-around-the-change guard keeps the dict-key example as
the failure a signature-watcher misses.

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

tests/test_routes_snippets.py

@@ -41,9 +41,8 @@ def test_service_functions_take_user_id():
 
 def test_agent_and_web_surfaces_stay_at_parity():
     """The MCP tools and the REST routes are two callers of one service; a
-    capability on one has to exist on the other (rule #33). This guard exists
-    because they drifted apart once: MCP had no delete or `locations`, and the
-    web side had no `system_ids` and no near-duplicate gate."""
+    capability on one has to exist on the other. Two doors maintained
+    separately drift — a delete on one, a near-duplicate gate on the other."""
     from scribe.mcp.tools import snippets as tools
     from scribe.routes import snippets as routes
 
@@ -65,13 +64,13 @@ def test_agent_and_web_surfaces_stay_at_parity():
         assert "system_ids" in inspect.getsource(route)
     assert "find_duplicate_note" in inspect.getsource(routes.create_snippet_route)
 
-    # The drift check (#2086) reaches both: recording a verdict, and filtering
+    # The drift check reaches both: recording a verdict, and filtering
     # the list by one. A verdict an agent records has to be visible to the human
     # looking at the same corpus, or the two surfaces disagree about what's rotten.
     assert "verification" in inspect.signature(tools.list_snippets).parameters
     assert "verification" in inspect.getsource(routes.list_snippets_route)
 
-    # The near-duplicate report (#2088) reaches both. The web side can only hand
+    # The near-duplicate report reaches both. The web side can only hand
     # a group to the merge flow if it can get the groups in the first place.
     assert callable(getattr(tools, "find_duplicate_snippets", None))
     assert callable(getattr(routes, "duplicate_snippets_route", None))
@@ -90,7 +89,7 @@ def test_project_scoping_reaches_every_caller():
 def test_location_lookup_reaches_every_caller():
     """The reverse lookup — "what already lives here?" — has to be askable from
     both surfaces, or an agent and a human get different answers about the same
-    file (rule #33)."""
+    file."""
     from scribe.mcp.tools import snippets as tools
     from scribe.routes import snippets as routes
     from scribe.services import snippets as svc
@@ -102,7 +101,7 @@ def test_location_lookup_reaches_every_caller():
 
 def test_update_field_map_matches_service_kwargs():
     """Every field the PATCH route forwards must be a real update_snippet kwarg
-    (rule #33 interface-contract parity)."""
+    (interface-contract parity)."""
     from scribe.routes import snippets as routes
     from scribe.services import snippets as svc
     params = inspect.signature(svc.update_snippet).parameters