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/business-logic-separation.mdc

@@ -9,7 +9,7 @@ description: Enforce business logic separation between frontend and backend
 
 All business logic, data processing, and domain rules MUST be implemented in the backend services layer. The frontend is purely for presentation and user interaction.
 
-## ✅ ALLOWED in Frontend ([components/](mdc:components/), [hooks/](mdc:hooks/), [clients/](mdc:clients/))
+## ✅ ALLOWED in Frontend ([src/components/](mdc:src/components/), [src/hooks/](mdc:src/hooks/), [src/clients/](mdc:src/clients/))
 
 ### Components
 - UI rendering and presentation logic
@@ -73,7 +73,7 @@ const calculateTeamVelocity = (sprints) => {
 // This belongs in services/team-analytics.ts
 ```
 
-## ✅ REQUIRED in Backend ([services/](mdc:services/), [app/api/](mdc:app/api/))
+## ✅ REQUIRED in Backend ([src/services/](mdc:src/services/), [src/app/api/](mdc:src/app/api/))
 
 ### Services Layer
 - All business rules and domain logic