feat: Frontend CSS refactoring and test improvements

Frontend:
- Refactored CSS architecture with new utility classes
- Updated dashboard components styling
- Improved responsive grid system
- Enhanced typography and variables
- Updated E2E and integration tests

Added:
- Claude Code slash commands for validation
- SSH tunnel and start test scripts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

reports-app/frontend/tests/e2e/auth/login.spec.js

@@ -38,9 +38,7 @@ test.describe('Authentication - Login Flow', () => {
     
     // Button should remain disabled with empty fields
     expect(await loginPage.isLoginButtonDisabled()).toBe(true);
-    
-    // Verify form validation classes are applied
-    const hasInvalidFields = await loginPage.hasInvalidField();
+
     // Note: validation might not show invalid state until user interaction
   });