test(retrieval): two source guards read the pipeline where the rule arms now live (milestone 456 step 2, #4904)

CI run 8137 had two failures, both source-scanning guards whose property
moved to the pipeline. The property itself still held:

- test_every_surface_name_is_a_real_telemetry_source looked for
  source="<name>" literals. The rule arms now record under their spec field,
  so the spec is the join key, read from RULE_ARMS.
- test_every_hook_rule_search_says_which_project_it_is_for counted 4 direct
  searches in plugin_context. It now expects 0 there, so a copied arm fails
  the count. It also asserts that the pipeline has exactly one search and
  that its keyword literal carries project_id and never everywhere.

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

tests/test_retrieval_surfaces.py

@@ -67,9 +67,16 @@ def test_every_surface_name_is_a_real_telemetry_source():
     # a literal, so that one name is satisfied by the constant holding it.
     from scribe.services.reply_preferences import SOURCE
 
+    # The rule arms record through the one pipeline (milestone 456), where
+    # `source` is the spec's own field — so for them the spec IS the string
+    # `record_retrieval` receives, and the join key is checked against it.
+    from scribe.services.retrieval_pipeline import RULE_ARMS
+
+    via_pipeline = {arm.source for arm in RULE_ARMS}
     missing = [
         s.name for s in rs.SURFACES.values()
-        if f'source="{s.name}"' not in blob and s.name != SOURCE
+        if f'source="{s.name}"' not in blob
+        and s.name != SOURCE and s.name not in via_pipeline
     ]
     assert not missing, (
         f"these surfaces can be tuned but never measured: {missing}. The "