Enhance ESLint configuration and improve code consistency

- Added '@typescript-eslint/no-unused-vars' rule to ESLint configuration for better variable management in TypeScript files.
- Updated database.ts to ensure consistent logging format.
- Refactored AuthController and CashflowController to improve variable naming and maintainability.
- Added spacing for better readability in multiple controller methods.
- Adjusted error handling in middleware and repository files for improved clarity.
- Enhanced various service and repository methods to ensure consistent return types and error handling.
- Made minor formatting adjustments across frontend components for improved user experience.

eslint.config.js

@@ -7,7 +7,8 @@ import {defineConfig, globalIgnores} from 'eslint/config';
 
 // Shared rules for all TypeScript files
 const sharedRules = {
-  'padding-line-between-statements': ['error', {blankLine: 'always', prev: '*', next: 'return'}]
+  'padding-line-between-statements': ['error', {blankLine: 'always', prev: '*', next: 'return'}],
+  '@typescript-eslint/no-unused-vars': ['error', {argsIgnorePattern: '^_', varsIgnorePattern: '^_', caughtErrorsIgnorePattern: '^_'}]
 };
 
 export default defineConfig([