ADR-013 Phase 2: meta_path import guard (re-review fix)

shopdb/plugins/__init__.py

@@ -80,6 +80,16 @@ class PluginManager:
         self.loader.verifier = verifier
         self.migration_manager.verifier = verifier
 
+        # Install (or clear) the import guard that verifies every `plugins.*`
+        # import against a trusted signature. This is what covers the core
+        # request handlers that do `from plugins.<name>.models import ...`, which
+        # never pass through the loader (findings #1, #2).
+        from . import importguard
+        if verifier.require_signed:
+            importguard.install(plugins_dir, verifier)
+        else:
+            importguard.uninstall()
+
         # Load enabled plugins
         self._load_enabled_plugins()