chore: refactor project structure and clean up unused components

- Updated `TODO.md` to reflect new testing tasks and final structure expectations.
- Simplified TypeScript path mappings in `tsconfig.json` for better clarity.
- Revised business logic separation rules in `.cursor/rules` to align with new directory structure.
- Deleted unused client components and services to streamline the codebase.
- Adjusted import paths in scripts to match the new structure.

.cursor/rules/services.mdc

@@ -1,5 +1,5 @@
 ---
-globs: services/*.ts
+globs: src/services/*.ts
 ---
 
 # Services Rules
@@ -7,7 +7,7 @@ globs: services/*.ts
 1. Services MUST contain ALL PostgreSQL queries
 2. Services are the ONLY layer allowed to communicate with the database
 3. Each service MUST:
-   - Use the pool from [services/database.ts](mdc:services/database.ts)
+   - Use the pool from [src/services/database.ts](mdc:src/services/database.ts)
    - Implement proper transaction management
    - Handle errors and logging
    - Validate data before insertion
@@ -37,6 +37,6 @@ export class MyService {
 
 ❌ FORBIDDEN:
 
-- Direct database queries outside services
+- Direct database queries outside src/services
 - Raw SQL in API routes
 - Database logic in components