api login method

interface/api/accounts/request/auth.yaml

@@ -8,10 +8,26 @@ components:
       properties:
         clientId:
           type: string
+          description: Client identifier bound to refresh token lifecycle and client policy checks.
         deviceId:
           type: string
         login:
           $ref: ../../../models/auth/login_data.yaml#/components/schemas/LoginData
 
+    ApiLoginRequest:
+      allOf:
+        - $ref: ./auth.yaml#/components/schemas/LoginRequest
+        - type: object
+          additionalProperties: false
+          required:
+            - clientId
+            - deviceId
+            - clientSecret
+          properties:
+            clientSecret:
+              type: string
+              format: password
+              description: Client secret for `client_secret_post` authentication.
+
     RefreshTokenRequest:
       $ref: ../../../models/auth/client_refresh_token.yaml#/components/schemas/ClientRefreshToken