Teach an English word as a video supercut

Turn one English word into a self-contained HLS lesson:

intro.ts  (word /IPA/ · 中文 gloss · usage + Volcano TTS)
   ⋯ EXT-X-DISCONTINUITY
[supercut] every season2 clip where the word is spoken  (search-app /api/playlist, COS URLs)
   ⋯ EXT-X-DISCONTINUITY
cta.ts    (关注王建硕 + Volcano TTS)
= search-app/out/<word>.m3u8

No MP4 is burned — only the two cards are rendered as tiny .ts, re-encoded to match the supercut's codec so they play in any HLS player.

Prerequisites (check once)