Add Plugin: html2video-for-mcode

[Wzdhehe]

What changes

Add Plugin: html2video-for-mcode at plugins/Wzdhehe/html2video-for-mcode.

A Skill that turns a topic, outline, or script into a narrated MP4: HTML slides with staged
entrance animations, a TTS voiceover, burned-in subtitles, and an ASR pass that verifies the
voiceover says what the script says.

User value

After installing, a MiniMax Code user can ask in plain language:

帮我把这份大纲做成一条 60 秒的中文口播视频:三张关键数字、结尾一句行动号召,用深色科技主题,加中文字幕。

and get:

out/final.mp4      1920×1080 (or 1080×1920 vertical), H.264 + AAC
out/subs.srt       subtitles for platform upload
out/slide-*.mp4    per-slide segments
preview/*.png      terminal-state frames

What makes it more than a slide exporter:

• Timing is measured, never hand-written — every slide duration and animation entrance time is
  derived from the TTS audio via ffprobe, so the picture can never lag behind the voiceover.
• Every slide carries a title layer and a detail layer on separate animation stages, so no page
  is just a headline.
• Animations are baked into the video — capture steps frames deterministically instead of
  screen-recording.
• Rendering is gated — a static check refuses slides with undefined CSS variables, missing
  images, external resources, or entrance animations without an animation class: the silent
  failure modes that otherwise ship a broken-looking video while every script reports success.

Plugin submission checklist

• Plugin lives at plugins/<github-owner>/<plugin-name>.
• plugin.json name matches the Plugin directory.
• README.md includes a real example prompt and expected result (bilingual: README.md +
  README.zh-CN.md).
• LICENSE and plugin.json declare an open-source license (MIT).
• Required executables, accounts, paid services, and supported platforms are disclosed
  (Node 18+, ffmpeg/ffprobe, Playwright Chromium; MiniMax API key or Token Plan for voice and
  ASR; Windows/macOS/Linux; PowerShell caveat documented).
• Network destinations and data handled by the plugin are disclosed
  (api.minimaxi.com / api.minimax.io for ASR only when invoked; voice via mcode connectors
  or mmx-cli; image fetching only from URLs the user passes; no telemetry).
• No credentials, private endpoints, hidden telemetry, installers, symlinks, or native binaries
  are included. The ASR script reads its key from an environment variable or CLI flag at
  runtime and never writes it.
• Every scaffold TODO has been replaced.
• npm run check passes.

Evidence

$ node scripts/validate.mjs
OK   plugin Wzdhehe/html2video-for-mcode
Validated 27 hosted Plugins and all examples.
$ echo $?
0

$ node --test          # 107 tests: 106 pass, 1 fail
✖ hosted Plugin rejects symlinks that can escape its package root

The single failure is a Windows checkout artifact, not a content problem: that test creates a
symlink fixture, and creating symlinks on Windows requires Developer Mode or elevation
(EPERM: operation not permitted, symlink …). It reproduces identically on a clean checkout
without this Plugin. CI runs on ubuntu-latest, where it passes. npm run validate — the part of
npm run check that inspects Plugins — passes with exit code 0.

Manual end-to-end test (Windows, Node 24, ffmpeg-static):

• Scaffolded a project, generated 8 TTS clips, ran plan-timings.mjs → every slide duration and
  stage entrance time derived from measured audio.
• check-slides.mjs correctly rejects slides with undefined CSS variables (--coral-a/--coral-b),
  missing images, external font links, and data-stage without an animation class; clean slides pass.
• capture.mjs --mode motion produced 143 frames for an 8.6s slide; frame-diff (PSNR) confirms the
  staged entrance actually renders at its scheduled time (inf before the entrance, ~14 dB across it).
• build-video.mjs --asr produced a 14.20s MP4 matching the expected duration exactly, full decode
  clean, out/subs.srt generated, and per-sentence ASR parts produced.
• Theme gate: 13 themes pass WCAG contrast checks; a low-contrast brand accent (#FFB84D on white)
  is rejected with a non-zero exit code, a compliant one (#C2410C) passes.
• ASR comparison verified offline against synthetic transcripts: simplified Chinese passes,
  traditional characters (Cantonese voice) and mismatched numbers fail with exit code 1.

Full disclosure of dependencies, network access, and data handling is in the Plugin README.

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