feat(feishu): extract embedded video/media from post (rich text) messages (#21786)

* feat(feishu): extract embedded video/media from post (rich text) messages

Previously, parsePostContent() only extracted embedded images (img tags)
from rich text posts, ignoring embedded video/audio (media tags). Users
sending post messages with embedded videos would not have the media
downloaded or forwarded to the agent.

Changes:
- Extend parsePostContent() to also collect media tags with file_key
- Return new mediaKeys array alongside existing imageKeys
- Update resolveFeishuMediaList() to download embedded media files
  from post messages using the messageResource API
- Add appropriate logging for embedded media discovery and download

* Feishu: keep embedded post media payloads type-safe

* Feishu: format post parser after media tag extraction

---------

Co-authored-by: laopuhuluwa <laopuhuluwa@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

extensions/feishu/src/bot.ts

@@ -453,14 +453,19 @@ async function resolveFeishuMediaList(params: {
   const out: FeishuMediaInfo[] = [];
   const core = getFeishuRuntime();
 
-  // Handle post (rich text) messages with embedded images
+  // Handle post (rich text) messages with embedded images/media.
   if (messageType === "post") {
-    const { imageKeys } = parsePostContent(content);
-    if (imageKeys.length === 0) {
+    const { imageKeys, mediaKeys: postMediaKeys } = parsePostContent(content);
+    if (imageKeys.length === 0 && postMediaKeys.length === 0) {
       return [];
     }
 
-    log?.(`feishu: post message contains ${imageKeys.length} embedded image(s)`);
+    if (imageKeys.length > 0) {
+      log?.(`feishu: post message contains ${imageKeys.length} embedded image(s)`);
+    }
+    if (postMediaKeys.length > 0) {
+      log?.(`feishu: post message contains ${postMediaKeys.length} embedded media file(s)`);
+    }
 
     for (const imageKey of imageKeys) {
       try {
@@ -497,6 +502,40 @@ async function resolveFeishuMediaList(params: {
       }
     }
 
+    for (const media of postMediaKeys) {
+      try {
+        const result = await downloadMessageResourceFeishu({
+          cfg,
+          messageId,
+          fileKey: media.fileKey,
+          type: "file",
+          accountId,
+        });
+
+        let contentType = result.contentType;
+        if (!contentType) {
+          contentType = await core.media.detectMime({ buffer: result.buffer });
+        }
+
+        const saved = await core.channel.media.saveMediaBuffer(
+          result.buffer,
+          contentType,
+          "inbound",
+          maxBytes,
+        );
+
+        out.push({
+          path: saved.path,
+          contentType: saved.contentType,
+          placeholder: "<media:video>",
+        });
+
+        log?.(`feishu: downloaded embedded media ${media.fileKey}, saved to ${saved.path}`);
+      } catch (err) {
+        log?.(`feishu: failed to download embedded media ${media.fileKey}: ${String(err)}`);
+      }
+    }
+
     return out;
   }