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>

tests/conftest.py

@@ -221,9 +221,10 @@ def _no_moment_delivery(request):
 
     update_task, the create_* record tools and the milestone tools now hand
     back the rules mounted on the moment they mark, and finding those is two
-    database reads. Patched BENEATH the attach, at `deliver_for_act`, because
-    the tools bind `attach_moment_rules` by name at import time. Skipped for
-    integration tests; tests/test_moment_delivery.py binds the real one.
+    database reads. Patched BENEATH the attach, at `deliver_for_act`, so the
+    attach itself — its fail-open and its non-dict pass-through — still runs.
+    Skipped for integration tests; tests/test_moment_delivery.py binds the
+    real one.
     """
     if request.node.get_closest_marker("integration"):
         yield