SubMiner/backlog/tasks/task-5 - Eliminate-type-duplication-between-renderer.ts-and-types.ts.md

id, title, status, assignee, created_date, labels, milestone, dependencies, references, priority

id	title	status	assignee	created_date	labels	milestone	dependencies	references	priority
TASK-5	Eliminate type duplication between renderer.ts and types.ts	To Do		2026-02-11 08:20	refactor types renderer	Codebase Clarity & Composability		src/renderer/renderer.ts src/types.ts src/main.ts	high

Description

renderer.ts locally redefines 20+ interfaces/types that already exist in types.ts: MergedToken, SubtitleData, MpvSubtitleRenderMetrics, Keybinding, SubtitlePosition, SecondarySubMode, all Jimaku/Kiku types, RuntimeOption types, SubsyncSourceTrack, SubsyncManualPayload, etc.

This creates divergence risk — changes in types.ts don't automatically propagate to the renderer's local copies.

Additionally, DEFAULT_MPV_SUBTITLE_RENDER_METRICS and sanitizeMpvSubtitleRenderMetrics() exist only in renderer.ts despite being shared concerns (main.ts also has DEFAULT_MPV_SUBTITLE_RENDER_METRICS).

Acceptance Criteria

• #1 All shared types are imported from types.ts — no local redefinitions in renderer.ts
• #2 DEFAULT_MPV_SUBTITLE_RENDER_METRICS lives in one canonical location (types.ts or a shared module)
• #3 sanitizeMpvSubtitleRenderMetrics moved to a shared module importable by both main and renderer
• #4 TypeScript compiles cleanly with no type errors
• #5 Renderer-only types (ChordAction, KikuModalStep, KikuPreviewMode) can stay local