Add authentication, user management, and database migration features

- Implement OAuth 2.0 and PAT authentication methods
- Add user management, roles, and profile functionality
- Add database migrations and admin user scripts
- Update services for authentication and user settings
- Add protected routes and permission hooks
- Update documentation for authentication and database access

backend/src/routes/configuration.ts

@@ -4,6 +4,7 @@ import { join, dirname } from 'path';
 import { fileURLToPath } from 'url';
 import { logger } from '../services/logger.js';
 import { clearEffortCalculationConfigCache, getEffortCalculationConfigV25 } from '../services/effortCalculation.js';
+import { requireAuth, requirePermission } from '../middleware/authorization.js';
 import type { EffortCalculationConfig, EffortCalculationConfigV25 } from '../config/effortCalculation.js';
 import type { DataCompletenessConfig } from '../types/index.js';
 
@@ -13,9 +14,13 @@ const __dirname = dirname(__filename);
 
 const router = Router();
 
+// All routes require authentication and manage_settings permission
+router.use(requireAuth);
+router.use(requirePermission('manage_settings'));
+
 // Path to the configuration files
 const CONFIG_FILE_PATH = join(__dirname, '../../data/effort-calculation-config.json');
-const CONFIG_FILE_PATH_V25 = join(__dirname, '../../data/effort-calculation-config-v25.json');
+const CONFIG_FILE_PATH_V25 = join(__dirname, '../../data/effort-calculation-config.json');
 const COMPLETENESS_CONFIG_FILE_PATH = join(__dirname, '../../data/data-completeness-config.json');
 
 /**