test(backup): run 9076's three failures (#5673, #5674)

- The audit-wording guard now reads both branches of a conditional action
  ("backup.made" if ok else "backup.failed"), and its self-test covers that.
- The Backups save test no longer asserts the session's tz, which sign-in
  state sets, not the test.
- The restore integration test uses the app's own metadata. all_metadata
  without plugin dirs imports the `plugins` package as the tests do; loading
  by path under the loader's names is only for `steward restore`. Loading by
  path in the shared test process had mapped traefik and unifi tables a
  second time for later tests.

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

steward/backup/restore.py

@@ -41,7 +41,8 @@ def all_metadata(plugin_dirs: list[Path] | None = None) -> MetaData:
     restore runs before anything else would load them. Plugins are found in
     `plugin_dirs` (the bootstrap's, bundled first) and loaded by path under
     the same module names the app gives them, so a plugin the app already
-    loaded isn't mapped twice. Without dirs: the repository's plugins/."""
+    loaded isn't mapped twice. Without dirs (tests, a checkout): the
+    `plugins` package, as the tests import it."""
     import importlib
     import sys
 
@@ -51,15 +52,18 @@ def all_metadata(plugin_dirs: list[Path] | None = None) -> MetaData:
     from steward.models.base import Base
 
     roots = [Path(d).resolve() for d in (plugin_dirs or [Path(steward.__file__).parent.parent / "plugins"])]
+    by_path = bool(plugin_dirs)
     names = sorted({p.name for root in roots if root.is_dir() for p in root.iterdir()
                     if (p / "__init__.py").exists() and (p / "models.py").exists()})
     for name in names:
         if f"plugins.{name}.models" in sys.modules or f"_steward_plugin_{name}.models" in sys.modules:
             continue          # already mapped, under one name or the other
-        path = resolve_plugin_path(roots, name)
         try:
-            package = _import_plugin(name, path)
-            importlib.import_module(f"{package.__name__}.models")
+            if by_path:
+                package = _import_plugin(name, resolve_plugin_path(roots, name)).__name__
+            else:
+                package = f"plugins.{name}"
+            importlib.import_module(f"{package}.models")
         except Exception:     # a plugin that won't load: its tables are left as pg_restore put them
             logger.warning("Restore: couldn't load plugin %r's tables", name, exc_info=True)
     return Base.metadata