refactor: move customer identification to agent node

- Add identify_customer_node to Agent class for customer lookup
- Webhook now only passes customer_phone to agent state
- Customer identification happens in agent flow: START -> identify_customer -> llm_call -> tool_node -> END

src/naliiabot/bot/agent/agent.py

@@ -6,6 +6,7 @@ from langchain_core.runnables import RunnableConfig
 from typing import Literal, Callable, Any, Union
 from .schemas import MessagesState
 from dataclasses import dataclass
+import json
 
 
 @dataclass
@@ -134,10 +135,12 @@ class Agent:
         """Construye el grafo de estado completo."""
         agent_builder = StateGraph(MessagesState)
 
+        agent_builder.add_node("identify_customer", self._identify_customer_node)
         agent_builder.add_node("llm_call", self._llm_call_node)
         agent_builder.add_node("tool_node", self._tool_node)
 
-        agent_builder.add_edge(START, "llm_call")
+        agent_builder.add_edge(START, "identify_customer")
+        agent_builder.add_edge("identify_customer", "llm_call")
         agent_builder.add_conditional_edges(
             "llm_call", self._should_continue, {"tool_node": "tool_node", END: END}
         )
@@ -145,6 +148,45 @@ class Agent:
 
         return agent_builder
 
+    def _identify_customer_node(self, state: MessagesState) -> dict:
+        """
+        Nodo de identificación del cliente.
+        Busca el cliente por teléfono y actualiza el estado.
+        """
+        from ..logger import logger
+
+        customer_phone = state.get("customer_phone", "")
+        if not customer_phone:
+            return {"customer_name": "Cliente Anónimo", "customer_id": 0}
+
+        find_customer_tool = self._tools_by_name.get("find_customer_by_identifier")
+        if not find_customer_tool:
+            logger.warning("Tool find_customer_by_identifier not found")
+            return {"customer_name": "Cliente Final", "customer_id": 0}
+
+        try:
+            result = find_customer_tool.invoke({"identifier": customer_phone})
+            customer_data = json.loads(result) if result else {}
+
+            if isinstance(customer_data, list):
+                customer_data = customer_data[0] if customer_data else {}
+
+            if customer_data and customer_data.get("id"):
+                customer_name = customer_data.get("party", {}).get(
+                    "name", "Cliente Final"
+                )
+                customer_id = customer_data.get("id", 0)
+                logger.info(
+                    f"Cliente identificado: {customer_name} (ID: {customer_id})"
+                )
+                return {"customer_name": customer_name, "customer_id": customer_id}
+            else:
+                logger.info(f"Cliente no encontrado para teléfono: {customer_phone}")
+                return {"customer_name": "Cliente Nuevo", "customer_id": 0}
+        except Exception as e:
+            logger.error(f"Error identificando cliente: {e}")
+            return {"customer_name": "Cliente Final", "customer_id": 0}
+
     def _llm_call_node(self, state: MessagesState) -> dict:
         """
         Nodo LLM: Decide siguiente acción o responde.