feat: add governed customer service agent

app/core/config.py

@@ -24,6 +24,7 @@ class Settings(BaseSettings):
     jwt_public_key_path: str = "config/jwt/jwt-public.pem"
     jwt_clock_skew_seconds: int = Field(default=30, ge=0)
     visitor_token_ttl_seconds: int = Field(default=900, ge=60, le=3600)
+    customer_service_phone: str = Field(default="15936583816", pattern=r"^1\d{10}$")
     mysql_dsn: str
     mysql_pool_size: int = Field(default=5, ge=1)
     mysql_max_overflow: int = Field(default=10, ge=0)

app/core/contracts.py

@@ -11,6 +11,8 @@ class AgentRequestMetadata(BaseModel):
     locale: str | None = None
     client_version: str | None = None
     ui_entry: str | None = None
+    # 仅由受理服务写入 Outbox，客户端 API 不接收该字段。
+    chitchat_streak: int = Field(default=0, ge=0, le=5)
 
 
 class AgentRequest(BaseModel):