feat(assistant): implement spec 021 chat assistant flow with semantic contracts

backend/src/api/routes/__init__.py

@@ -1,10 +1,23 @@
-# Lazy loading of route modules to avoid import issues in tests
-# This allows tests to import routes without triggering all module imports
-
-__all__ = ['plugins', 'tasks', 'settings', 'connections', 'environments', 'mappings', 'migration', 'git', 'storage', 'admin', 'reports']
-
-def __getattr__(name):
-    if name in __all__:
-        import importlib
-        return importlib.import_module(f".{name}", __name__)
-    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+# [DEF:backend.src.api.routes.__init__:Module]
+# @TIER: STANDARD
+# @SEMANTICS: routes, lazy-import, module-registry
+# @PURPOSE: Provide lazy route module loading to avoid heavyweight imports during tests.
+# @LAYER: API
+# @RELATION: DEPENDS_ON -> importlib
+# @INVARIANT: Only names listed in __all__ are importable via __getattr__.
+
+__all__ = ['plugins', 'tasks', 'settings', 'connections', 'environments', 'mappings', 'migration', 'git', 'storage', 'admin', 'reports', 'assistant']
+
+
+# [DEF:__getattr__:Function]
+# @TIER: TRIVIAL
+# @PURPOSE: Lazily import route module by attribute name.
+# @PRE: name is module candidate exposed in __all__.
+# @POST: Returns imported submodule or raises AttributeError.
+def __getattr__(name):
+    if name in __all__:
+        import importlib
+        return importlib.import_module(f".{name}", __name__)
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+# [/DEF:__getattr__:Function]
+# [/DEF:backend.src.api.routes.__init__:Module]