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_mcp_tool_processes.py

@@ -2,7 +2,7 @@
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
-from tests.helpers import fake_note
+from tests.helpers import FakeMCP, fake_note
 
 
 pytestmark = pytest.mark.usefixtures("_bind_user")
@@ -172,18 +172,11 @@ def test_register_attaches_every_tool_in_the_module():
     import inspect
 
     from scribe.mcp.tools import processes
-    names: list[str] = []
+    mcp = FakeMCP()
 
-    class FakeMcp:
-        def tool(self, name):
-            names.append(name)
-            def deco(fn):
-                return fn
-            return deco
-
-    processes.register(FakeMcp())
+    processes.register(mcp)
     public = {
         name for name, obj in vars(processes).items()
         if inspect.iscoroutinefunction(obj) and not name.startswith("_")
     }
-    assert set(names) == public
+    assert set(mcp.names) == public