align(4909b): every write with a path gets its rule check, whether or not prior art matched

The write-path rule arm ran only past the notes guard: a write whose code
matched no snippet, issue or lesson returned before any rule was searched.
It now runs before that guard, on `code or path`, and a write that matched
nothing but a rule still returns the rule lines.

Operator ruling (2026-10-05): yes. A rule about the file being written does
not depend on a snippet resembling it.

Cost: one more rule search per write that matched no prior art, with its
own embedding (the query is `code or path`, not the notes arm's concept
query, so the per-request memo does not cover it). Plus the preference slot
from (c) on those writes.

Expected telemetry shift, to be read on its own once this reaches main:
write_path_rule calls rise toward write_path's count (14 days to 2026-10-22:
write_path_rule 4,634 against write_path 3,786 — the notes arm skips trivial
payloads, the rule arm does not, so the rule arm will now exceed it). Its
zero-result share rises too, since the newly covered writes are the ones
that matched nothing in the notes corpus.

Tests: the gate test is inverted (a write with no prior art still gets its
rule check); the design-only write now runs the rule arm on its path; two
notes-arm tests read the write_path row instead of any row, since the rule
arm writes its own.

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

tests/test_write_path_trigger.py

@@ -614,7 +614,9 @@ async def test_trivial_payload_skips_the_semantic_arm_entirely():
         out = await pc.build_write_path_hint(1, "src/x.py", code="x = 1")
     assert out["context"] == "" and out["note_ids"] == []
     search.assert_not_called()
-    rec.assert_not_called()
+    # The rule arm still checks the write and logs its own row; the notes arm
+    # logs none.
+    assert [c for c in rec.call_args_list if c.kwargs["source"] == "write_path"] == []
 
 
 @pytest.mark.asyncio
@@ -798,7 +800,8 @@ async def test_telemetry_records_the_query_actually_sent():
          patch.object(pc, "semantic_search_notes", AsyncMock(return_value=[])), \
          patch.object(pc, "record_retrieval", rec):
         await pc.build_write_path_hint(1, "src/x.py", code=REAL_CODE)
-    logged = rec.call_args.kwargs["query"]
+    row = next(c for c in rec.call_args_list if c.kwargs["source"] == "write_path")
+    logged = row.kwargs["query"]
     assert logged.startswith("debounce(fn, wait=0.25)")
     assert "nonlocal timer" not in logged