fix(wecom): raise the image upload cap to the platform's 10 MB (#8174)

* fix(wecom): raise the image upload cap to the platform's 10 MB

`send_file` capped images at 2 MB and files at 20 MB. 2 MB is the *voice*
limit in WeCom's aibot media-upload protocol; images are allowed up to 10 MB
(developer.work.weixin.qq.com/document/path/101917). Every 2-10 MB image was
therefore dropped before upload, and the turn arrived without its chart.

Raise the image cap to 10 MB. The 512 KiB chunk size keeps a 10 MB upload at
20 chunks, well under the protocol's 100-chunk limit.

* docs(changelog): record the WeCom image-cap fix

Adds the Unreleased -> Fixed -> channels entry for #8174 to CHANGELOG.md and
CHANGELOG_zh.md.

CHANGELOG.md

@@ -60,6 +60,12 @@ This section accumulates work toward the **2.3.0** milestone
 
 ### Fixed
 
+- **channels:** WeCom no longer drops images between 2 MB and 10 MB. The
+  adapter capped image uploads at 2 MB — the voice limit in the same protocol —
+  so a larger chart was skipped before upload and the turn arrived without it.
+  The cap now matches the platform's 10 MB for images; the 20 MB file limit is
+  unchanged. ([#8174])
+
 - **threads:** Deleting a conversation on Windows no longer fails with
   `Failed to delete local thread data.` when the workspace holds a file whose
   path exceeds `MAX_PATH`. The thread directory is now resolved through the
@@ -16341,3 +16347,4 @@ with **180 merged pull requests** since the first 2.0 milestone tag.
 [#8126]: https://github.com/bytedance/deer-flow/pull/8126
 [#8131]: https://github.com/bytedance/deer-flow/pull/8131
 [#8151]: https://github.com/bytedance/deer-flow/pull/8151
+[#8174]: https://github.com/bytedance/deer-flow/pull/8174

CHANGELOG_zh.md

@@ -26,6 +26,9 @@
 
 ### 修复
 
+- **通道：** 企业微信不再丢弃 2–10 MB 的图片。此前适配器把图片上限定为 2 MB（同一协议中语音的限制），
+  超出即在上传前被跳过，消息到达时缺少图片。现在图片上限与平台的 10 MB 对齐；普通文件 20 MB 的限制不变。([#8174])
+
 - **通道：** WeCom 群聊中 `@机器人 /new` 这类带提及的命令现在按命令执行。WeCom 会把提及保留在
   正文里，而命令识别要求裸的前导 `/`，于是群里的 `/new`、`/status` 被当成聊天轮次。现在仅在命令
   识别时跳过前导提及；普通聊天保留提及，`/connect` 行为不变。与飞书、钉钉的处理一致。([#8118])
@@ -12872,3 +12875,4 @@ DeerFlow 2.0 是围绕"超级智能体"框架的彻底重写，核心包含子
 [#8064]: https://github.com/bytedance/deer-flow/pull/8064
 [#8118]: https://github.com/bytedance/deer-flow/pull/8118
 [#8126]: https://github.com/bytedance/deer-flow/pull/8126
+[#8174]: https://github.com/bytedance/deer-flow/pull/8174

backend/app/channels/wecom.py

@@ -447,7 +447,11 @@ class WeComChannel(Channel):
             return False
 
         media_type = "image" if attachment.is_image else "file"
-        size_limit = 2 * 1024 * 1024 if attachment.is_image else 20 * 1024 * 1024
+        # aibot media upload limits: image 10 MB, voice 2 MB, video 10 MB,
+        # file 20 MB (https://developer.work.weixin.qq.com/document/path/101917).
+        # The image cap used to be 2 MB — the voice limit — which dropped every
+        # 2-10 MB image before it was uploaded.
+        size_limit = 10 * 1024 * 1024 if attachment.is_image else 20 * 1024 * 1024
         if attachment.size > size_limit:
             logger.warning(
                 "[WeCom] %s too large (%d bytes), skipping: %s",

backend/tests/test_channel_file_attachments.py

@@ -1822,3 +1822,64 @@ def test_embedded_upload_retries_claim_collision(tmp_path, monkeypatch, channel_
     advertised = "/mnt/user-data/uploads/report_2.pdf"
     assert advertised in result.text
     assert synced == ([] if mounted else [(advertised, payload)])
+
+
+class TestWecomMediaSizeLimits:
+    """WeCom's aibot media upload accepts images up to 10 MB.
+
+    The adapter used to cap images at 2 MB — the *voice* limit in the same
+    protocol — and silently skipped anything larger before uploading it, so a
+    2-10 MB chart never reached the user. See
+    https://developer.work.weixin.qq.com/document/path/101917
+    """
+
+    @staticmethod
+    def _channel():
+        from types import SimpleNamespace
+
+        from app.channels.wecom import WeComChannel
+
+        channel = WeComChannel(MessageBus(), {})
+        channel._ws_client = SimpleNamespace(reply=AsyncMock())
+        channel._upload_media_ws = AsyncMock(return_value="media-1")
+        return channel
+
+    def test_image_above_two_megabytes_reaches_the_uploader(self, tmp_path):
+        channel = self._channel()
+        msg = _file_reply(tmp_path, channel_name="wecom")
+        channel._ws_frames[msg.thread_ts] = {"body": {"msgid": msg.thread_ts}}
+        channel._ws_stream_ids[msg.thread_ts] = "stream-1"
+
+        path = tmp_path / "chart.png"
+        path.write_bytes(b"\x89PNG\r\n\x1a\n")
+        attachment = ResolvedAttachment(
+            "/mnt/user-data/outputs/chart.png",
+            path,
+            "chart.png",
+            "image/png",
+            5 * 1024 * 1024,
+            True,
+        )
+
+        assert _run(channel.send_file(msg, attachment)) is True
+        channel._upload_media_ws.assert_awaited_once()
+
+    def test_image_above_the_platform_limit_is_still_skipped(self, tmp_path):
+        channel = self._channel()
+        msg = _file_reply(tmp_path, channel_name="wecom")
+        channel._ws_frames[msg.thread_ts] = {"body": {"msgid": msg.thread_ts}}
+        channel._ws_stream_ids[msg.thread_ts] = "stream-1"
+
+        path = tmp_path / "huge.png"
+        path.write_bytes(b"\x89PNG\r\n\x1a\n")
+        attachment = ResolvedAttachment(
+            "/mnt/user-data/outputs/huge.png",
+            path,
+            "huge.png",
+            "image/png",
+            11 * 1024 * 1024,
+            True,
+        )
+
+        assert _run(channel.send_file(msg, attachment)) is False
+        channel._upload_media_ws.assert_not_awaited()