feat(visitor): Implement visitor chat functionality and enhance customer service interactions

- Added a new visitor chat API endpoint (`/api/chat/visitor`) to allow unauthenticated users to engage in conversations without requiring customer data.
- Introduced a visitor context dependency to manage visitor interactions seamlessly.
- Enhanced the chat API to support explicit session termination and improved response handling for customer service interactions.
- Updated the database configuration to include Redis client support for caching visitor data.
- Added a new customer note repository to persist user notes independently of the L1 profile slots.

This update significantly improves the customer service experience by enabling visitor interactions and ensuring efficient data handling for both registered and unregistered users.

app/model/schemas.py

@@ -6,8 +6,22 @@ from typing import Any, Literal
 
 from pydantic import BaseModel, Field
 
-AgentType = Literal["customer", "advisor", "analyst", "risk"]
-TokenType = Literal["customer", "staff", "service"]
+AgentType = Literal["customer", "advisor", "analyst", "risk", "visitor"]
+TokenType = Literal["customer", "staff", "service", "visitor"]
+IntentType = Literal[
+    "product_consult",
+    "policy_interpret",
+    "faq",
+    "chit_chat",
+    "save_note",
+    "reject",
+    "transfer_human",
+    "fallback",
+    "holding_query",
+    "transaction_query",
+    "risk_assessment_query",
+    "suitability_check",
+]
 
 
 class AuthContext(BaseModel):
@@ -58,6 +72,8 @@ class ChatResponseData(BaseModel):
     reply: str
     agent_type: AgentType
     has_disclaimer: bool = False
+    intent: IntentType | None = Field(default=None, description="仅 customer 返回")
+    transfer_to_human: bool = Field(default=False, description="仅 customer 返回")
 
 
 class ApiResponse(BaseModel):
@@ -65,3 +81,20 @@ class ApiResponse(BaseModel):
     message: str = "ok"
     data: Any = None
     trace_id: str
+
+
+class VisitorChatRequest(BaseModel):
+    """游客对话请求（免认证）。"""
+
+    message: str = Field(..., min_length=1, max_length=8000)
+    session_id: str | None = None
+
+
+class VisitorChatResponseData(BaseModel):
+    """游客对话响应。"""
+
+    session_id: str
+    reply: str
+    intent: IntentType
+    has_disclaimer: bool = False
+    transfer_to_human: bool = False