fix(moments): the tools import the delivery module, and the tool-list cache leaves the swept directory (milestone 458 step 4a, #4922)

Two guards caught 7865313:

- test_mcp_tool_processes reads every coroutine in a tool module's
  namespace as a tool, and a name-imported attach_moment_rules looked
  like one. All seven modules now call moment_delivery.attach_moment_rules,
  and the parity guard accepts the attribute form.
- The session-ledger convention: a file in a swept directory must be a
  .ids ledger. The tool-list cache describes the install, not the
  context, so it moves to its own directory, scribe-moment, where a
  compaction does not sweep it.

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

src/scribe/mcp/tools/lessons.py

@@ -19,7 +19,7 @@ from scribe.services import systems as systems_svc
 from scribe.services import trash as trash_svc
 from scribe.mcp.tools import systems as systems_tools
 from scribe.services.note_usage import attach_usage, record_pulled
-from scribe.services.moment_delivery import attach_moment_rules
+from scribe.services import moment_delivery
 
 
 # The payload shape lives in the service (`lesson_to_dict`), shared with the
@@ -246,7 +246,7 @@ async def create_lesson(
         await _offer_candidates(uid, data, what, when_to_apply, project_id)
     elif no_rule.strip():
         await _name_convergence(uid, data, note.id)
-    return await attach_moment_rules(uid, "create_lesson", {"project_id": project_id}, data)
+    return await moment_delivery.attach_moment_rules(uid, "create_lesson", {"project_id": project_id}, data)
 
 
 async def _name_convergence(uid: int, data: dict, lesson_id: int) -> None: