[pallaoro]

From a client call: captions on vertical clips were large and wrapped to three lines, there was no way to fix a caption's words or to get a video's transcript out, and on a small laptop screen the Captions tab could not be reached.

What changes

• Caption size is a share of the frame's shorter side, not its height. On a 1080×1920 video "Medium" was 106 px (17 characters a line, against captions of up to 32); it is now 59 px, the same as on a 1080p wide video. Wide and square videos do not change. Existing vertical projects get smaller captions.
• Two lines at most: a caption's length is cut down where the chosen line length would not fit on two lines, and wrapLines no longer spends a third line when words do not split evenly (it affects text overlays too, only where they wrapped to more lines than the width needs).
• Extra small size (XS, 0.035).
• Correct the words: the Captions panel lists what is said on the timeline, cue by cue; editing one saves it to the clip's transcript (PUT /api/assets/{id}/transcript/cues), so every video cut from that clip shows it.
• Download transcript: GET /api/assets/{id}/transcript/text, one [m:ss] words line per cue. Linked from the Captions panel and from a library video's hover controls.
• Short screens: the rail's tabs are icons only under 820 px of height, and the column scrolls.

Known limit

Asking for a transcript in another language replaces the kept one, corrections included (there is one transcript per clip). Stated in agent.md.

Checked

• pnpm typecheck, pnpm test (314), pnpm test:e2e pass; new unit tests for sizing, the two-line rule over every size, line length and shape, and the VTT round trip; e2e for both routes.
• Run locally in a browser at 1271×628: all six tabs reachable, the panel scrolls, a vertical video at Large shows two even lines, a corrected cue is saved and shown.
• Not checked in a browser: the library tile's download button (it shows only for videos on the media service, which a local run does not have).