feat: complete phase 2 -- multi-agent routing, interrupt TTL, escalation, templates

- Intent classification with LLM structured output (single/multi/ambiguous)
- Discount agent with apply_discount and generate_coupon tools
- Interrupt manager with 30-min TTL auto-expiration and retry prompts
- Webhook escalation module with exponential backoff retry (max 3)
- Three vertical industry templates (e-commerce, SaaS, fintech)
- Template loading in AgentRegistry
- Enhanced supervisor prompt with dynamic agent descriptions
- 153 tests passing, 90.18% coverage

backend/tests/unit/test_graph.py

@@ -7,7 +7,8 @@ from unittest.mock import AsyncMock, MagicMock
 
 import pytest
 
-from app.graph import SUPERVISOR_PROMPT, build_agent_nodes, build_graph
+from app.graph import build_agent_nodes, build_graph, classify_intent
+from app.intent import ClassificationResult, IntentTarget
 
 if TYPE_CHECKING:
     from app.registry import AgentRegistry
@@ -38,7 +39,51 @@ class TestBuildGraph:
         graph = build_graph(sample_registry, mock_llm, mock_checkpointer)
         assert graph is not None
 
-    def test_supervisor_prompt_contains_routing_info(self) -> None:
-        assert "order_lookup" in SUPERVISOR_PROMPT
-        assert "order_actions" in SUPERVISOR_PROMPT
-        assert "fallback" in SUPERVISOR_PROMPT
+    def test_graph_has_classifier_attached(self, sample_registry: AgentRegistry) -> None:
+        mock_llm = MagicMock()
+        mock_llm.bind_tools = MagicMock(return_value=mock_llm)
+        mock_llm.with_structured_output = MagicMock(return_value=mock_llm)
+        mock_checkpointer = AsyncMock()
+        mock_classifier = MagicMock()
+
+        graph = build_graph(
+            sample_registry, mock_llm, mock_checkpointer, intent_classifier=mock_classifier
+        )
+        assert graph.intent_classifier is mock_classifier
+        assert graph.agent_registry is sample_registry
+
+    def test_graph_without_classifier(self, sample_registry: AgentRegistry) -> None:
+        mock_llm = MagicMock()
+        mock_llm.bind_tools = MagicMock(return_value=mock_llm)
+        mock_llm.with_structured_output = MagicMock(return_value=mock_llm)
+        mock_checkpointer = AsyncMock()
+
+        graph = build_graph(sample_registry, mock_llm, mock_checkpointer)
+        assert graph.intent_classifier is None
+
+
+@pytest.mark.unit
+class TestClassifyIntent:
+    @pytest.mark.asyncio
+    async def test_returns_none_without_classifier(self) -> None:
+        graph = MagicMock()
+        graph.intent_classifier = None
+        result = await classify_intent(graph, "hello")
+        assert result is None
+
+    @pytest.mark.asyncio
+    async def test_calls_classifier(self) -> None:
+        expected = ClassificationResult(
+            intents=(IntentTarget(agent_name="order_lookup", confidence=0.9, reasoning="test"),),
+        )
+        mock_classifier = AsyncMock()
+        mock_classifier.classify = AsyncMock(return_value=expected)
+
+        graph = MagicMock()
+        graph.intent_classifier = mock_classifier
+        graph.agent_registry = MagicMock()
+        graph.agent_registry.list_agents = MagicMock(return_value=())
+
+        result = await classify_intent(graph, "check order")
+        assert result is not None
+        assert result.intents[0].agent_name == "order_lookup"