Updated changes in backend

RIT-EMS-main/PROJECT_OVERVIEW.md

@@ -21,12 +21,10 @@ The system addresses critical administrative bottlenecks such as:
 ## 2. Technology Stack
 
 ### Backend
-* **Core Framework:** Spring Boot 3.2.5 (Java 17)
-* **API Architecture:** RESTful Controllers
-* **Data Access Layer:** Spring Data JPA with Hibernate
-* **Database:** MySQL (local schema: `ems_db`)
-* **Security:** Spring Security (endpoints are permit-all at filter level, but validation and role checks occur inside controller services; password encryption via `BCryptPasswordEncoder`)
-* **Developer Tools:** Project Lombok, Spring Boot DevTools
+* **Core Backend Service:** Firebase (Firestore Database, Firebase Authentication)
+* **API Architecture:** Serverless client-side interceptor via `firebaseBackend.ts` which intercepts `/api/*` requests in the browser and processes them directly against Firestore collections.
+* **Database:** Cloud Firestore (Collections: `ems_users`, `ems_events`, `ems_notes`, `ems_classes`)
+* **Security:** Checked via frontend role verification and Firestore Security Rules.
 
 ### Frontend
 * **Core Framework:** React 19, TypeScript, Vite
@@ -42,7 +40,7 @@ The system addresses critical administrative bottlenecks such as:
 
 ## 3. Database Schema & Architecture
 
-The system contains four principal entities mapped via JPA.
+The system contains four principal Firestore collections.
 
 ### A. User Entity (`users`)
 Holds institutional account profiles, login credentials, permissions, and roles.
@@ -133,37 +131,6 @@ Used for pinning warnings, reminders, or notifications on the main calendar.
 
 ## 5. Directory Layout & Architecture
 
-### Backend Layout
-```text
-backend/src/main/java/com/ems/backend/
-├── BackendApplication.java       # Boot Entry Point
-├── config/
-│   ├── DataInitializer.java     # Verify and populate seed users on startup
-│   ├── DataSeeder.java          # Verify and seed mock events on startup
-│   ├── SecurityConfig.java      # CORS and filter rules configuration
-│   └── CustomUserDetailsService # Loads core user details for Spring Security
-├── controller/
-│   ├── AdminController.java     # CRUD endpoints for Users (/api/admin/users)
-│   ├── AuthController.java      # Login endpoints (/api/auth)
-│   ├── ClassController.java     # Class mappings and promotions (/api/classes)
-│   ├── EventController.java     # Propose, approve, batch-create events (/api/events)
-│   ├── HealthController.java    # System and database connectivity check (/api/health)
-│   └── NoteController.java      # Board notices and institutional logs (/api/notes)
-├── dto/
-│   └── LoginRequest.java        # Login DTO container
-├── model/
-│   ├── BaseEntity.java          # Audited fields ID superclass
-│   ├── ClassMapping.java        # Class config model
-│   ├── Event.java               # Core event proposal model
-│   ├── InstitutionalNote.java   # Date-based board notices model
-│   └── User.java                # Account profiles model
-└── repository/
-    ├── ClassRepository.java
-    ├── EventRepository.java     # Custom JPA Query for timing conflict resolution
-    ├── InstitutionalNoteRepository.java
-    └── UserRepository.java
-```
-
 ### Frontend Layout
 ```text
 frontend/src/