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/app/agents/__init__.py

@@ -7,6 +7,7 @@ from typing import TYPE_CHECKING
 if TYPE_CHECKING:
     from langchain_core.tools import BaseTool
 
+from app.agents.discount import apply_discount, generate_coupon
 from app.agents.fallback import fallback_respond
 from app.agents.order_actions import cancel_order
 from app.agents.order_lookup import get_order_status, get_tracking_info
@@ -16,6 +17,8 @@ _TOOL_MAP: dict[str, BaseTool] = {
     "get_tracking_info": get_tracking_info,
     "cancel_order": cancel_order,
     "fallback_respond": fallback_respond,
+    "apply_discount": apply_discount,
+    "generate_coupon": generate_coupon,
 }