SubMiner/backlog/tasks/task-78 - Modularize-config-definitions-and-validation-by-domain.md

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

id	title	status	assignee	created_date	updated_date	labels	dependencies	priority
TASK-78	Modularize config definitions and validation by domain	To Do		2026-02-18 11:43	2026-02-18 11:43	config refactor maintainability	TASK-69 TASK-72	high

Description

Config defaults and resolution are still concentrated in large files (src/config/definitions.ts, src/config/service.ts). This task splits config schema/defaults/validation into domain modules while preserving a single composed public config API.

Suggestions

• Organize by domain (anki, subtitle, jellyfin, anilist, launcher, runtime).
• Keep one composition root that merges domain validators and defaults.
• Prefer small reusable validator helpers over per-field inline logic.

Action Steps

1. Define domain module boundaries for defaults + validation rules.
2. Extract domain validators with shared primitives and warning builder.
3. Compose resolved config in a central aggregator module.
4. Keep ConfigService external API stable.
5. Expand tests for domain-level validation and composed config output.
6. Update config docs to reflect module ownership and extension workflow.

Acceptance Criteria

• #1 Config definitions/validation are split by domain with clear ownership
• #2 ConfigService API remains backward-compatible
• #3 Validation behavior remains stable under existing tests
• #4 New domain-level tests prevent regression in future config additions

Definition of Done

• #1 Config and core tests pass
• #2 Documentation updated for config extension workflow