When config.json schema changes between versions, register a migration
function in src/config/migrations.js. On startup, loadSiteConfig() detects
the stored version, runs all migrations forward, and writes the result back.
Users never see the migration — it runs silently and the rest of the app
only ever sees the current schema.
Includes:
- v0 → v1: normalize dns from string to object
- v1 → v2: add dns.provider field (default 'technitium')
- Forward compat: configs from future versions left untouched
- Idempotent: re-running on already-migrated config is a no-op
- Safe: no user data is removed during migration
21 unit tests covering edge cases: null input, forward compat, corrupt
JSON, missing parent dirs, idempotency, full migration chain.
- Create src/config/paths.js for all file paths and env vars
- Create src/config/site.js for site configuration loading
- Create src/config/index.js as unified config export
- Prepare for server.js modularization (Phase 2.1)
Part of deslopification roadmap: break 1997-line server.js into layers