A 视频投稿动态 (`DYNAMIC_TYPE_AV`) carries no body at all: the API
answers `desc: null` and the content is the archive card, so `title`
(and `{title}` in caption formats) stayed empty for the most common
dynamic type. Audited 24 live dynamics: every dynamic that *has* text
(a 图文 post, a forward, a text post) keeps it in
`module_dynamic.desc.text` — only the AV card has none, so the video
title now stands in, mirroring pixiv whose `title` is the artwork title
rather than post text.
Also records two API observations in comments/docs: an id that cannot
exist answers `4101105 请求数据发生错误` (kept on the permanent arm), and
the feed endpoints strip `desc.text` so only the detail endpoint shows
whether a post has text.
Fetch `t.bilibili.com/<id>`, `www.bilibili.com/opus/<id>`,
`t.bilibili.com/h5/dynamic/detail/<id>` and `m.bilibili.com/dynamic/<id>`
through the anonymous `/x/polymer/web-dynamic/v1/detail` endpoint (no
cookie, no WBI signature; the site adds the device cookies
`/x/frontend/finger/spi` hands out, which is what lifts bilibili's
`-352` risk control).
Media: the `major.draw` grid (`.gif` sources become animations, the rest
photos with a downscaled `@518w.jpg` thumbnail used both as preview and
as the oversized fallback), an attached video's cover, and the quoted
dynamic's media for forwards. The video stream itself is not resolved;
`b23.tv` short links stay unmatched (they mostly point at videos, so
matching them would turn a silently ignored link into a failure reply).
`-352`/`-412` map to a retryable error so the queue backs off instead of
dropping the post; a removed dynamic (`500`) is permanent.
Registry-driven, so no bot-side code changes beyond the site lists in the
command replies; found while researching nazurin and
telegram-bili-feed-helper (see BILIBILI_PLAN.md).
YoursFunny