refactor(go): avoid duplicate realtime protocol payloads

docs/architecture/iot-data-platform-principles.md

@@ -52,7 +52,7 @@ flowchart LR
 | MySQL | `vehicle_daily_mileage` | Queryable daily mileage | vin, date, protocol, daily mileage, source mileage | temporary vehicle keys, generic metric key/value rows, per-frame raw details |
 | MySQL | `vehicle_identity_binding` | Manual identity mapping | vin, plate, phone, device id | registration history |
 | MySQL | `jt808_registration` | JT808 registration and auth trace | phone, device id, plate, auth code, vin match state, first/latest seen | GB32960 or MQTT records |
-| Redis | `vehicle:latest:{vehicleKey}` | Latest merged realtime state | cross-protocol latest fields | historical data |
+| Redis | `vehicle:latest:{vehicleKey}` | Latest merged realtime state | cross-protocol latest fields only | full parsed payloads and historical data |
 | Redis | `vehicle:realtime-raw:{protocol}:{vehicleKey}` | Latest full realtime protocol state | latest protocol parsed payload | historical data |
 
 ## Event Envelope Rules

docs/architecture/production-data-plane-inventory.md

@@ -81,9 +81,9 @@ Redis 使用 DB 50，定位为实时缓存，不作为历史事实来源。
 
 | Key 族 | 用途 |
 | --- | --- |
-| `vehicle:latest:{vehicleKey}` | 跨协议合并后的最新实时快照 |
+| `vehicle:latest:{vehicleKey}` | 跨协议合并后的最新核心字段快照，不重复保存完整 parsed |
 | `vehicle:latest:{vehicleKey}:{protocol}` | 单协议最新快照 |
-| `vehicle:realtime-raw:{protocol}:{vehicleKey}` | 单协议最新完整 parsed 状态 |
+| `vehicle:realtime-raw:{protocol}:{vehicleKey}` | 单协议最新完整 parsed 状态，是实时完整协议字段的唯一 Redis 副本 |
 | `vehicle:online:{vehicleKey}` | 在线状态和 TTL |
 | `vehicle:protocols:{vehicleKey}` | 当前车辆最近出现过的协议集合 |
 | `vehicle:last_seen` | 最近活跃车辆排序集合 |

docs/go-version-data-flow.html

@@ -638,7 +638,7 @@
             <thead><tr><th>接口类型</th><th>数据源</th><th>说明</th></tr></thead>
             <tbody>
               <tr><td>VIN 是否在线</td><td>Redis online key</td><td>TTL 内有数据即在线，默认 TTL 600 秒。</td></tr>
-              <tr><td>VIN 实时数据</td><td>Redis merged snapshot</td><td>跨协议合并 fields，并保留各协议 ProtocolData。</td></tr>
+              <tr><td>VIN 实时数据</td><td>Redis latest snapshot</td><td>跨协议合并核心 fields；完整协议字段通过 realtime-raw 查询。</td></tr>
               <tr><td>单协议实时 RAW</td><td>Redis realtime-raw</td><td>查看某 VIN/phone 在某协议下最新 parsed 全量字段。</td></tr>
             </tbody>
           </table>
@@ -722,7 +722,7 @@
         </div>
         <div class="ok">
           <strong>实时多协议合并</strong><br>
-          Redis 同时保留 latest snapshot、protocol snapshot、realtime-raw，既能看统一实时，也能追单协议原始字段。
+          Redis latest snapshot 只保留统一实时核心字段；完整协议 parsed 只放 realtime-raw，避免重复缓存大 JSON。
         </div>
         <div class="ok">
           <strong>身份解析降级</strong><br>