feat: add dingtalk chat channel (#16183)

### What does this PR do?
This PR adds a new DingTalk chat channel integration and hardens the
inbound callback path.

### Summary
- Adds DingTalk as a selectable chat channel in the UI and backend
channel registry.
- Adds the DingTalk chat channel icon asset.
- Acknowledges DingTalk Stream callbacks and deduplicates repeated
inbound messages to avoid duplicate replies.

web/src/pages/user-setting/chat-channel/constant/index.tsx

@@ -8,6 +8,7 @@ import { IChatChannelInfoMap } from '../interface';
 export enum ChatChannelKey {
   CLICKCLACK = 'clickclack',
   DISCORD = 'discord',
+  DINGTALK = 'dingtalk',
   FEISHU = 'feishu',
   GOOGLECHAT = 'googlechat',
   IRC = 'irc',
@@ -48,6 +49,7 @@ const channelIcon = (key: ChatChannelKey) => (
 const CHANNEL_NAMES: Record<ChatChannelKey, string> = {
   [ChatChannelKey.CLICKCLACK]: 'ClickClack',
   [ChatChannelKey.DISCORD]: 'Discord',
+  [ChatChannelKey.DINGTALK]: 'DingTalk',
   [ChatChannelKey.FEISHU]: 'Feishu / Lark',
   [ChatChannelKey.GOOGLECHAT]: 'Google Chat',
   [ChatChannelKey.IRC]: 'IRC',
@@ -160,6 +162,21 @@ export const ChatChannelFormFields: Record<ChatChannelKey, FormFieldConfig[]> =
         placeholder: '1234567890',
       },
     ],
+    [ChatChannelKey.DINGTALK]: [
+      {
+        label: 'Client ID',
+        name: 'config.credential.client_id',
+        type: FormFieldType.Text,
+        required: true,
+        placeholder: 'dingxxxxxxxxxxxx',
+      },
+      {
+        label: 'Client Secret',
+        name: 'config.credential.client_secret',
+        type: FormFieldType.Password,
+        required: true,
+      },
+    ],
     [ChatChannelKey.FEISHU]: [
       {
         label: 'App ID',

web/src/pages/user-setting/chat-channel/index.tsx

@@ -61,6 +61,7 @@ const ChatChannel = () => {
       (id) =>
         [
           ChatChannelKey.DISCORD,
+          ChatChannelKey.DINGTALK,
           ChatChannelKey.FEISHU,
           ChatChannelKey.TELEGRAM,
           ChatChannelKey.QQBOT,