fix: resolve ruff lint errors in Phase 2 code

- Move intent imports to TYPE_CHECKING block in graph.py (TC001)
- Rename test classes to CapWords convention (N801)
- Fix line length violations across test files (E501)
- Auto-fix import sorting (I001)

backend/tests/integration/test_phase2_checkpoints.py

@@ -90,7 +90,7 @@ def _agent(name: str, desc: str, perm: str = "read") -> AgentConfig:
 # ---------------------------------------------------------------------------
 
 @pytest.mark.integration
-class TestCheckpoint1_OrderQueryRouting:
+class TestCheckpoint1OrderQueryRouting:
     """Verify intent classifier routes order queries to order_lookup."""
 
     @pytest.mark.asyncio
@@ -161,7 +161,7 @@ class TestCheckpoint1_OrderQueryRouting:
 # ---------------------------------------------------------------------------
 
 @pytest.mark.integration
-class TestCheckpoint2_MultiIntentSequential:
+class TestCheckpoint2MultiIntentSequential:
     """Verify multi-intent classified and hint injected for sequential execution."""
 
     @pytest.mark.asyncio
@@ -235,7 +235,7 @@ class TestCheckpoint2_MultiIntentSequential:
 # ---------------------------------------------------------------------------
 
 @pytest.mark.integration
-class TestCheckpoint3_AmbiguousClarification:
+class TestCheckpoint3AmbiguousClarification:
     """Verify ambiguous messages trigger clarification prompt."""
 
     @pytest.mark.asyncio
@@ -263,7 +263,9 @@ class TestCheckpoint3_AmbiguousClarification:
         mock_classifier.classify = AsyncMock(return_value=ClassificationResult(
             intents=(),
             is_ambiguous=True,
-            clarification_question="Could you please provide more details about what you need help with?",
+            clarification_question=(
+                "Could you please provide more details about what you need help with?"
+            ),
         ))
         graph.intent_classifier = mock_classifier
         mock_registry = MagicMock()
@@ -294,7 +296,7 @@ class TestCheckpoint3_AmbiguousClarification:
 # ---------------------------------------------------------------------------
 
 @pytest.mark.integration
-class TestCheckpoint4_InterruptTTLAutoCancel:
+class TestCheckpoint4InterruptTTLAutoCancel:
     """Verify interrupt TTL expiration triggers auto-cancel and retry prompt."""
 
     @pytest.mark.asyncio
@@ -361,7 +363,7 @@ class TestCheckpoint4_InterruptTTLAutoCancel:
 # ---------------------------------------------------------------------------
 
 @pytest.mark.integration
-class TestCheckpoint5_WebhookEscalation:
+class TestCheckpoint5WebhookEscalation:
     """Verify webhook escalation sends POST and retries on failure."""
 
     @pytest.mark.asyncio
@@ -442,7 +444,7 @@ class TestCheckpoint5_WebhookEscalation:
 # ---------------------------------------------------------------------------
 
 @pytest.mark.integration
-class TestCheckpoint6_EcommerceTemplate:
+class TestCheckpoint6EcommerceTemplate:
     """Verify e-commerce template loads with correct agents."""
 
     def test_ecommerce_template_loads_4_agents(self) -> None:

backend/tests/integration/test_routing.py

@@ -24,7 +24,6 @@ from app.registry import AgentConfig
 from app.session_manager import SessionManager
 from app.ws_handler import dispatch_message
 
-
 # ---------------------------------------------------------------------------
 # Helpers
 # ---------------------------------------------------------------------------
@@ -78,10 +77,22 @@ def _state(*, interrupt: bool = False, data: dict | None = None):
 
 
 AGENTS = (
-    AgentConfig(name="order_lookup", description="Looks up orders", permission="read", tools=["get_order_status", "get_tracking_info"]),
-    AgentConfig(name="order_actions", description="Modifies orders", permission="write", tools=["cancel_order"]),
-    AgentConfig(name="discount", description="Applies discounts", permission="write", tools=["apply_discount", "generate_coupon"]),
-    AgentConfig(name="fallback", description="Handles unclear requests", permission="read", tools=["fallback_respond"]),
+    AgentConfig(
+        name="order_lookup", description="Looks up orders",
+        permission="read", tools=["get_order_status", "get_tracking_info"],
+    ),
+    AgentConfig(
+        name="order_actions", description="Modifies orders",
+        permission="write", tools=["cancel_order"],
+    ),
+    AgentConfig(
+        name="discount", description="Applies discounts",
+        permission="write", tools=["apply_discount", "generate_coupon"],
+    ),
+    AgentConfig(
+        name="fallback", description="Handles unclear requests",
+        permission="read", tools=["fallback_respond"],
+    ),
 )
 
 
@@ -136,7 +147,9 @@ class TestSingleIntentRouting:
     @pytest.mark.asyncio
     async def test_routes_to_order_lookup(self) -> None:
         result = ClassificationResult(
-            intents=(IntentTarget(agent_name="order_lookup", confidence=0.95, reasoning="status query"),),
+            intents=(IntentTarget(
+                agent_name="order_lookup", confidence=0.95, reasoning="status query",
+            ),),
         )
         graph = _make_graph(result, [
             _tool_chunk("get_order_status", {"order_id": "1042"}, "order_lookup"),

backend/tests/integration/test_websocket.py

@@ -19,7 +19,6 @@ from app.interrupt_manager import InterruptManager
 from app.session_manager import SessionManager
 from app.ws_handler import dispatch_message
 
-
 # ---------------------------------------------------------------------------
 # Helpers
 # ---------------------------------------------------------------------------
@@ -182,7 +181,8 @@ class TestWebSocketInterruptApproval:
     @pytest.mark.asyncio
     async def test_interrupt_then_approve(self) -> None:
         st_int = _state(interrupt=True, data={"action": "cancel_order", "order_id": "1042"})
-        g = _graph(chunks=[], st=st_int, resume_chunks=[_chunk("Order 1042 cancelled.", "order_actions")])
+        resume = [_chunk("Order 1042 cancelled.", "order_actions")]
+        g = _graph(chunks=[], st=st_int, resume_chunks=resume)
         g_, sm, im, cb, ws = _setup(graph=g)
 
         # Send message -> triggers interrupt
@@ -209,7 +209,8 @@ class TestWebSocketInterruptApproval:
     @pytest.mark.asyncio
     async def test_interrupt_then_reject(self) -> None:
         st_int = _state(interrupt=True)
-        g = _graph(chunks=[], st=st_int, resume_chunks=[_chunk("Order remains active.", "order_actions")])
+        resume = [_chunk("Order remains active.", "order_actions")]
+        g = _graph(chunks=[], st=st_int, resume_chunks=resume)
         g_, sm, im, cb, ws = _setup(graph=g)
 
         await _send(ws, g_, sm, im, cb, content="Cancel order 1042")