Make db a required first parameter on all service functions (notes-service,
api-utils, tags, collaborators, attachments, rate-limit, sync/server).
This enables unit testing with in-memory databases via createTestDb().
Also removes the NODE_ENV=test bypass from rate-limit and adds optional
now parameter for time control in tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add noteCollaborators and noteUserState tables for sharing notes between
users. Implement access control helpers (canAccessNote, requireNoteAccess,
requireNoteOwnership) and collaborators CRUD service. Create API endpoints
for managing collaborators and searching users.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
