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_main.py

@@ -13,7 +13,7 @@ class TestMainModule:
         assert app.title == "Smart Support"
 
     def test_app_version(self) -> None:
-        assert app.version == "0.1.0"
+        assert app.version == "0.2.0"
 
     def test_agents_yaml_path_exists(self) -> None:
         assert AGENTS_YAML.name == "agents.yaml"