SubMiner/backlog/tasks/task-83 - Jellyfin-subtitle-delay-shift-to-adjacent-cue-without-seek-jumps.md

id, title, status, assignee, created_date, updated_date, labels, dependencies, priority, ordinal

id	title	status	assignee	created_date	updated_date	labels	dependencies	priority	ordinal
TASK-83	Jellyfin subtitle delay: shift to adjacent cue without seek jumps	Done		2026-03-02 00:06	2026-03-02 00:06			high	9003

Description

Add keybinding-friendly special commands that shift sub-delay to align current subtitle start with next/previous cue start, without sub-seek probing (avoid playback jump).

Scope:

• add special commands for next/previous line alignment;
• compute delta from active subtitle cue timeline (external subtitle file/URL, including Jellyfin-delivered URLs);
• apply add sub-delay <delta> and show OSD value;
• keep existing proxy OSD behavior for direct sub-delay keybinding commands.

Acceptance Criteria

• #1 New special commands exist for subtitle-delay shift to next/previous cue boundary.
• #2 Shift logic parses active external subtitle source timings (SRT/VTT/ASS) and computes delta from current sub-start.
• #3 Runtime applies delay shift without sub-seek and shows OSD feedback.
• #4 Direct sub-delay proxy commands also show OSD current value.
• #5 Tests added for cue parsing/shift behavior and IPC dispatch wiring.

Final Summary

Implemented no-jump subtitle-delay alignment commands:

• added __sub-delay-next-line and __sub-delay-prev-line special commands;
• added createShiftSubtitleDelayToAdjacentCueHandler to parse cue start times from active external subtitle source and apply add sub-delay delta from current sub-start;
• wired command handling through IPC runtime deps into main runtime;
• retained/extended OSD proxy feedback for sub-delay keybindings;
• updated configuration docs and added regression tests for subtitle-delay shift and IPC command routing.