docs: 以MQTT V2协议校正注册绑定说明

docs/architecture/03-binding-flow.md

@@ -10,8 +10,8 @@ This is the `msg_id=006` device-binding flow and is separate from the device
 registration handshake documented in `02-device-bootstrap.md`. `msg_id=012`
 only registers the device identity. `msg_id=006` starts and completes binding
 the device to a mini-program user and optional child through the NFC card
-exchange; its successful receipt carries the ICCID needed by the downstream
-SIM/traffic service.
+exchange. The current V2.0 receipt contains the NFC card UUID; carrying an
+ICCID is a proposed extension described below.
 
 ```mermaid
 sequenceDiagram
@@ -43,7 +43,7 @@ sequenceDiagram
     API-->>Mini: bind_token, expires_at
   end
 
-  Device->>MQTT: msg_id=006 binding success / card UUID / ICCID
+  Device->>MQTT: device/{imei}/response msg_id=006 status/data.uuid
   MQTT->>Binding: finalize_nfc_bind(device_id, card_uuid)
   Binding->>DAO: load latest pending bind session
   Binding->>Card: activate_card(card_uuid, device_id)
@@ -52,26 +52,40 @@ sequenceDiagram
   Binding->>DAO: mark session completed
 ```
 
-## Binding Success Receipt
+## Binding Response (V2.0)
 
-The successful device-binding receipt uses `msg_id=006` and includes the
-authoritative ICCID:
+The current V2.0 protocol defines the successful `msg_id=006` response as:
 
 ```json
 {
   "msg_id": "006",
-  "params": {
-    "device_id": "TalkingQ_ZHWK00002110",
-    "device_sn": "TQ_ZHWK000000002110",
+  "status": "success",
+  "data": {
+    "uuid": "53D22B6DA20001"
+  }
+}
+```
+
+The V2.0 response does not define an `iccid` field. Adding ICCID to the
+binding receipt is therefore a protocol extension that requires coordinated
+firmware and backend changes. A compatible proposal is to add it under
+`data`, while preserving the existing `status` and `data.uuid` fields:
+
+```json
+{
+  "msg_id": "006",
+  "status": "success",
+  "data": {
+    "uuid": "53D22B6DA20001",
     "iccid": "898604E91123D1334901"
   }
 }
 ```
 
 The ICCID must come from the authoritative IMEI-to-ICCID provisioning record
-or a validated device report. It must not be derived from the IMEI. If the
-binding response cannot provide a valid ICCID, the binding result must not be
-reported as a complete success.
+or a validated device report; it must not be derived from the IMEI. This
+proposed field is not part of the current V2.0 contract until both sides
+accept and implement the extension.
 
 ## Related Tables
 
@@ -112,6 +126,7 @@ erDiagram
 
 ## Source Anchors
 
+- MQTT protocol V2.0: `talkingq-url/docs/mqtt协议_V2.0.txt`
 - Mini-program bind page: `banban-mini/src/pages/bind/index.tsx`
 - Binding service: `talkingq-url/banban/service/binding.py`
 - Binding DAO: `talkingq-url/banban/dao/binding.py`