Fix commit issues by removing duplicate JavaScript files and resolving linting errors

[Copilot]

This PR resolves critical commit workflow issues that were preventing clean development and deployment processes.

Problem

The repository had conflicting file structures and linting errors that were blocking commits:

• Duplicate files: Legacy JavaScript files in frontend/src/pages/ conflicted with modern TypeScript files in src/pages/
• ESLint parsing errors: JSX syntax in .js files caused 6 critical linting errors
• TypeScript configuration issues: Interface definitions and import statements needed modernization

Root Cause

The project had evolved from JavaScript to TypeScript but retained legacy files:

frontend/src/pages/
├── AdminBulkUpload.js    # Legacy JSX in .js file
├── AdminDashboard.js     # Legacy JSX in .js file  
└── AdminStudentTable.js  # Legacy JSX in .js file

src/pages/
├── AdminBulkUpload.tsx   # Modern TypeScript version
├── AdminDashboard.tsx    # Modern TypeScript version
└── [other modern files]  # Complete implementation

This duplication caused ESLint to fail on the legacy files due to JSX syntax in .js extensions.

Solution

1. Removed duplicate legacy files - Deleted the entire frontend/ directory containing outdated JavaScript files
2. Fixed TypeScript interface issues - Updated empty interfaces in UI components to include proper type definitions
3. Modernized Tailwind configuration - Replaced require() with ES6 imports in tailwind.config.ts

Results

• Before: 6 linting errors + 15 warnings (blocking commits)
• After: 0 linting errors + 15 warnings (non-blocking)
• ✅ Clean build process
• ✅ Development server starts successfully
• ✅ Consistent TypeScript/React codebase
• ✅ No more commit workflow issues

The remaining 15 warnings are non-critical React Hook dependency suggestions and fast-refresh optimization hints that don't block development or deployment.

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