Prevent ordinary messages and forwarded nodes from combining video content with visible sibling segments or additional videos. Invalid combinations now fail before parsing side effects, media work, or bridge sends, while exact empty text placeholders remain compatible with a single video.
Cover group, private, temporary-session, CQ string, nested forward, cached forward, and protocol-builder paths. Preserve the existing standalone window-shake behavior and keep valid single-video messages unchanged.
Distinguish QQ-authoritative message sequences from local message IDs so group files and reply placeholders cannot become history anchors or be reused by protocol actions.
Filter QQ null roam records and migrate previously stored synthetic rows.
Fixes#254
Validate the public OneBot data.data field before converting JSON segments to the internal message element shape. Invalid payloads still return retcode 1400, but now identify the correct public field without reaching the QQ bridge.
Add Action-level regression coverage for issue #220.
Replace the open message bag with a validated discriminated union and preflight complete messages before uploads or sends. Return BAD_REQUEST for invalid or unsendable segments instead of dropping fields, sending partial content, or silently changing private messages.
DrSmoothl