refactor(backend): modular server split with new routes, persistence and agent layer

refactor: remove MUI, unify publisher pipeline, add shared component registry

fix: replace undefined __dirname with DATA_DIR in ESM server

fix: XSS escaping, DRY utils, agent undo batch, graceful shutdown

fix: prevent Y.Doc content duplication from seed race condition

fix: robust published article restore on container rebuild

fix: rename to Research Article Template Editor

refactor: rename to Science Article Template Editor, remove MDX export, fix settings drawer

fix: use manage-repos scope, public dataset, remove image proxy

fix: lazy-restore published article using OAuth token

feat: restore published article from HF dataset on startup

fix: accept /collab WebSocket upgrade without trailing slash

fix: replace express-ws with native ws to fix WebSocket binary handling

debug: enhance publish pipeline logging

fix: pass OAuth cookie token to Hocuspocus WebSocket auth

feat: auto-create private HF dataset using OAuth token

fix: flush Hocuspocus document to disk before publish

fix: use target=_blank for OAuth login (sandboxed iframe)

feat: implement proper HF OAuth flow

fix: OAuth login works inside HF Space iframe

fix: prevent express.static from serving index.html on /

refactor: remove doc URL parameter, single document per Space

feat: clean routing - /editor for auth, / for published article

fix: auth flow for publish and write access check

feat: add publish pipeline with HTML/PDF/thumbnail generation

feat: add HF OAuth authentication middleware

chore: initial commit