Backend context for LLM

Entrypoints: server/server.js and server/app.js. Config in config/drive.js. Routes → controllers → services. Middleware implements headers, rate limit, request ID, and access.

PostgreSQL/schema: database/postgresMigrations.js; Redis: redisService.js. Index/FTS: libraryIndexService. Source/file/covers: driveService. Pages: readerService. Metadata: metadataService and subfolder metadata. Jobs/cache/integrity/backup have their own services.

Large content should use Range/stream; do not do readFile without budget and format justification. Preserve Opaque ID, Fingerprint, CategoryPath, Work/File and Transient Drive Failure.

New route requires service/controller/router/test/doc API. Schema change requires migration + new/upgrade test. Backend does not serve spa; /sw.js only cleans legacy PWA.