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/test_moment_delivery.py

@@ -346,8 +346,10 @@ def _attached_names(path: Path) -> dict[str, set[str]]:
         if not isinstance(node, ast.AsyncFunctionDef):
             continue
         for call in ast.walk(node):
-            if (isinstance(call, ast.Call) and isinstance(call.func, ast.Name)
-                    and call.func.id == "attach_moment_rules" and len(call.args) > 1
+            func = call.func if isinstance(call, ast.Call) else None
+            name = (func.id if isinstance(func, ast.Name)
+                    else func.attr if isinstance(func, ast.Attribute) else "")
+            if (name == "attach_moment_rules" and len(call.args) > 1
                     and isinstance(call.args[1], ast.Constant)):
                 out.setdefault(node.name, set()).add(call.args[1].value)
     return out