refactor: establish standalone application boundary

app/tests/test_feature_boundaries.py

@@ -7,6 +7,27 @@ from pathlib import Path
 
 ROOT = Path(__file__).resolve().parents[1]
 FEATURES = ROOT / "backend" / "features"
+RETIRED_ROOT_MODULES = {
+    "advanced_strategies",
+    "alert_service",
+    "app_config",
+    "assistant_agent",
+    "chart_data_provider",
+    "heaven_agent",
+    "heaven_engine",
+    "ifind_client",
+    "llm_strategy",
+    "llm_stream",
+    "market_insights",
+    "mentor_agent",
+    "realtime_aggregator",
+    "screener",
+    "security",
+    "sentiment_engine",
+    "strategy_tracking",
+    "trade_journal",
+    "tushare_client",
+}
 
 
 class FeatureBoundaryTests(unittest.TestCase):
@@ -32,34 +53,7 @@ class FeatureBoundaryTests(unittest.TestCase):
                         violations.append(f"{path.relative_to(ROOT)} -> {name}")
         self.assertEqual(violations, [])
 
-    def test_backend_uses_root_compatibility_modules_only_at_declared_boundaries(self) -> None:
-        compatibility_modules = {
-            "advanced_strategies",
-            "alert_service",
-            "api_access",
-            "app_config",
-            "assistant_agent",
-            "chart_data_provider",
-            "heaven_agent",
-            "heaven_engine",
-            "ifind_client",
-            "llm_strategy",
-            "llm_stream",
-            "market_insights",
-            "mentor_agent",
-            "realtime_aggregator",
-            "screener",
-            "security",
-            "sentiment_engine",
-            "server",
-            "strategy_tracking",
-            "trade_journal",
-            "tushare_client",
-        }
-        allowed = {
-            "backend/application.py": {"api_access"},
-            "backend/features/screener/repository.py": {"sentiment_engine"},
-        }
+    def test_backend_does_not_import_retired_root_modules(self) -> None:
         violations = []
         for path in (ROOT / "backend").rglob("*.py"):
             relative = path.relative_to(ROOT).as_posix()
@@ -72,21 +66,15 @@ class FeatureBoundaryTests(unittest.TestCase):
                     names = [node.module]
                 for name in names:
                     root_name = name.split(".")[0]
-                    if (
-                        root_name in compatibility_modules
-                        and root_name not in allowed.get(relative, set())
-                    ):
+                    if root_name in RETIRED_ROOT_MODULES:
                         violations.append(f"{relative} -> {name}")
         self.assertEqual(violations, [])
 
-    def test_legacy_service_modules_are_compatibility_exports_only(self) -> None:
-        for filename in ("alert_service.py", "trade_journal.py", "strategy_tracking.py"):
-            tree = ast.parse((ROOT / filename).read_text(encoding="utf-8"))
-            definitions = [
-                node for node in tree.body
-                if isinstance(node, (ast.ClassDef, ast.FunctionDef, ast.AsyncFunctionDef))
-            ]
-            self.assertEqual(definitions, [], filename)
+    def test_retired_root_modules_are_absent(self) -> None:
+        present = sorted(
+            name for name in RETIRED_ROOT_MODULES if (ROOT / f"{name}.py").exists()
+        )
+        self.assertEqual(present, [])
 
     def test_each_migrated_feature_owns_one_application_service(self) -> None:
         expected = {