Collect and prioritize subtitle editing workflow improvements

[brucexuego]

ArcSub should provide a better subtitle editing experience, but we want improvements to be based on real subtitle editing workflows instead of assumptions.

We are collecting user feedback in this Discussion:

#28

This issue tracks the follow-up work to summarize and prioritize subtitle editing improvements.

Possible improvement areas

• Subtitle timing adjustment
• Split and merge subtitle rows
• Reading speed indicators
• Line length and line break checks
• Faster navigation between subtitles and video playback
• Source/translation comparison
• Speaker label review
• Batch cleanup for common subtitle issues
• Better editing experience for dialogue-heavy content

Acceptance criteria

• Feedback from the linked Discussion is summarized.
• Common subtitle editing needs are grouped into clear categories.
• Large ideas are split into smaller follow-up issues.
• Follow-up issues include clear expected behavior.
• Implementation tasks are separated from open-ended workflow research.
• The final recommendations are written for ArcSub's actual workflow.