refactor(tests): per-model fakes, FakeMCP and session mocks come from tests/helpers (#2825, milestone 296 area 1, batch 2)

Second pass over the tests/ ledger after bbee0d0. fake_record(**attrs) is the
one MagicMock-with-real-attributes builder (to_dict mirrors them; the
note-2109 hazard documented once); fake_note/fake_task/fake_snippet/
fake_project/fake_milestone/fake_system/fake_rulebook/fake_topic/fake_rule
carry each model's ordinary defaults on top of it, replacing 14 per-file
factories (two rulebook trios in tool-vs-service wordings, _fake_task, _fake_ms,
_fake_project, _plan_note, _fake_snippet, two _snippet adapters now one-liners
over fake_snippet). FakeMCP replaces the five closure-over-a-list registrar
fakes (+ _Recorder); loc() and design_token_stub() replace the paired _loc /
_token / _T stand-ins; every hand-built async_session mock (9 helper defs and
14 inline copies) now starts from make_mock_session(). Call sites rewritten by
AST with each file's former defaults made explicit, so behaviour is unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_recurrence.py

@@ -12,14 +12,12 @@ async def test_update_note_sets_started_at_on_in_progress():
     mock_note.started_at = None
     mock_note.recurrence_rule = None
 
-    mock_session = AsyncMock()
+    mock_session = make_mock_session()
     mock_result = MagicMock()
     mock_result.scalars.return_value.first.return_value = mock_note
     mock_session.execute = AsyncMock(return_value=mock_result)
     mock_session.commit = AsyncMock()
     mock_session.refresh = AsyncMock()
-    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
-    mock_session.__aexit__ = AsyncMock(return_value=False)
 
     with patch("scribe.services.notes.async_session", return_value=mock_session):
         from scribe.services.notes import update_note
@@ -36,14 +34,12 @@ async def test_update_note_sets_completed_at_on_done():
     mock_note.completed_at = None
     mock_note.recurrence_rule = None
 
-    mock_session = AsyncMock()
+    mock_session = make_mock_session()
     mock_result = MagicMock()
     mock_result.scalars.return_value.first.return_value = mock_note
     mock_session.execute = AsyncMock(return_value=mock_result)
     mock_session.commit = AsyncMock()
     mock_session.refresh = AsyncMock()
-    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
-    mock_session.__aexit__ = AsyncMock(return_value=False)
 
     with patch("scribe.services.notes.async_session", return_value=mock_session):
         from scribe.services.notes import update_note
@@ -60,14 +56,12 @@ async def test_update_note_clears_timestamps_on_todo():
     mock_note.completed_at = datetime(2026, 3, 15, tzinfo=timezone.utc)
     mock_note.recurrence_rule = None
 
-    mock_session = AsyncMock()
+    mock_session = make_mock_session()
     mock_result = MagicMock()
     mock_result.scalars.return_value.first.return_value = mock_note
     mock_session.execute = AsyncMock(return_value=mock_result)
     mock_session.commit = AsyncMock()
     mock_session.refresh = AsyncMock()
-    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
-    mock_session.__aexit__ = AsyncMock(return_value=False)
 
     with patch("scribe.services.notes.async_session", return_value=mock_session):
         from scribe.services.notes import update_note
@@ -85,14 +79,12 @@ async def test_update_note_preserves_started_at_if_already_set():
     mock_note.started_at = original_start
     mock_note.recurrence_rule = None
 
-    mock_session = AsyncMock()
+    mock_session = make_mock_session()
     mock_result = MagicMock()
     mock_result.scalars.return_value.first.return_value = mock_note
     mock_session.execute = AsyncMock(return_value=mock_result)
     mock_session.commit = AsyncMock()
     mock_session.refresh = AsyncMock()
-    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
-    mock_session.__aexit__ = AsyncMock(return_value=False)
 
     with patch("scribe.services.notes.async_session", return_value=mock_session):
         from scribe.services.notes import update_note
@@ -104,6 +96,7 @@ async def test_update_note_preserves_started_at_if_already_set():
 # ── Recurrence rule validation ────────────────────────────────────────────────
 
 import pytest
+from tests.helpers import make_mock_session
 
 
 def test_validate_interval_rule_valid():
@@ -233,14 +226,12 @@ async def test_spawn_recurring_tasks_creates_child():
     mock_task.due_date = date(2026, 3, 1)
     mock_task.recurrence_rule = {"type": "interval", "every": 3, "unit": "month"}
 
-    mock_session = AsyncMock()
+    mock_session = make_mock_session()
     mock_result = MagicMock()
     mock_result.scalars.return_value.all.return_value = [mock_task]
     mock_session.execute = AsyncMock(return_value=mock_result)
     mock_session.get = AsyncMock(return_value=mock_task)
     mock_session.commit = AsyncMock()
-    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
-    mock_session.__aexit__ = AsyncMock(return_value=False)
 
     mock_child = MagicMock()
     mock_child.id = 2
@@ -273,13 +264,11 @@ async def test_list_notes_multi_status_builds_in_clause():
     """list_notes with a list of statuses executes without error."""
     from unittest.mock import AsyncMock, MagicMock, patch
 
-    mock_session = AsyncMock()
+    mock_session = make_mock_session()
     mock_result = MagicMock()
     mock_result.scalars.return_value.all.return_value = []
     mock_session.execute = AsyncMock(return_value=mock_result)
     mock_session.scalar = AsyncMock(return_value=0)
-    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
-    mock_session.__aexit__ = AsyncMock(return_value=False)
 
     with patch("scribe.services.notes.async_session", return_value=mock_session):
         from scribe.services.notes import list_notes