add d1kt SSO integration: OAuth2 login via WebView + phone binding

sentence_api/models.py

@@ -155,6 +155,21 @@ class AuthResponse(BaseModel):
     user: UserPublic
 
 
+class SsoExchangeRequest(BaseModel):
+    access_token: str = Field(min_length=1, max_length=256)
+
+
+class SsoExchangeResponse(BaseModel):
+    token: str
+    user: UserPublic
+    phone_bound: bool = False
+    is_new_user: bool = False
+
+
+class SsoBindPhoneRequest(BaseModel):
+    phone: str = Field(min_length=1, max_length=20, pattern=r"^1[3-9]\d{9}$")
+
+
 class UserAdminItem(BaseModel):
     id: str
     username: str