Add comprehensive assessment system, curriculum management, and smart teaching enhancements

Super-admin: unify organizations data source; add users API with pagination/filters; wire users page to backend with pagination and filters; show organization name in Topbar

Fix RAG document creation and PDF upload functionality

feat: comprehensive system updates and improvements

feat: improve admin dashboard and users page UX

Fix double API call issue and add comprehensive improvements

feat: consolidate student dashboard and change default locale to English

fix: resolve runtime warnings and infinite re-render errors

Fix video system: Use Perplexity for real video URLs, remove fake video generation

✅ Complete Phase 3 Steps 3.1-3.2: Progress Tracking, Analytics & Performance Optimization

feat: Complete Phase 2.5 - Unified Smart Teaching Interface

Update ROADMAP_V3.md and STATUS.md with Phase 2.3 completion

Complete Phase 2.3: Adaptive Teaching Engine Integration + Add Phase 2.5: Unified Smart Teaching Interface

feat: Complete Phase 1 of ROADMAP_V3 - Smart Teaching Assessment Integration

feat: Add missing admin, super-admin, and teacher pages