QQ Official v2 API deduplicates passive messages by (msg_id, msg_seq).
The adapter reused msg_seq across multiple sends under the same inbound
msg_id, so multi-part text replies, rich media, and especially streaming
chunks (msg_seq pinned at 1) were rejected with:
40054005 消息被去重，请检查请求msgseq
Add a per-inbound-msg_id sequence allocator (next_reply_msg_seq) on
QQOfficialClient, backed by a bounded OrderedDict + asyncio lock, and use
it for C2C/group text sends and rich media. Streaming now advances
ctx['msg_seq'] per chunk. Proactive sends (no msg_id) fall back to the
existing global counter.
Closes#2290
dadachann