Add support for basic SRT subtitle import to Captions panel (#756)

* Add SRT subtitle import to the captions panel

[Modified from 0bd641b, 2026-03-28 08:46:23 -0400]

Parse .srt files into chunks and insert them as text elements on a new text track using the existing caption styling defaults. Displays a warning when malformed cues are skipped during import.

* Batch caption text insertion

[Modified from eece3bb, 2026-03-28 09:13:18 -0400]

Batch caption insertion in a BatchCommand so that undo will batch undo all subtitle insertion from either srt file or ai transcriptions.

* Move subtitle parsing into a shared interface

[Modified from e84404b, 2026-03-28 09:52:31 -0400]

Extracted the srt specific extraction behind a generic shared interface to allow easier adding of other subtitle formats in the future.

* Apply better default styling for subtitles.

[Modified from b5deec4, 2026-03-31 11:49:34 -0400]

Shrink font size, aim to layout 5% above bottom, keep subtitle width 80% of video, wrap text on new lines if too long.

* Update Captions Panel UI

Split captions panel into Generate and Import tabs as they are two different approaches for adding captions.

* Add biome formatting fixes

* Add .ass subtitle import support

Extend subtitle import to accept .ass files alongside .srt, map supported .ass styles onto imported text elements, and display warnings when unsupported .ass features are skipped.

* Change “Import subtitles” button style

* refactor: review fixes

* fix: convert subtitle times from seconds to ticks

* refactor: replace captions tab switcher with import action button

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Co-authored-by: Maze Winther <[email protected]>

Author: kcfancher