Refactor database environment variable usage across workflows and application code

- Updated Gitea workflows to standardize on `DB_NAME` instead of `DB_DATABASE` for database name references.
- Modified deployment, backup, reset, and restore workflows to ensure consistent environment variable usage.
- Removed dotenv dependency and preload script, transitioning to environment variable management directly in scripts.
- Adjusted application code to utilize `DB_NAME` for database connections and logging.
- Enhanced README to reflect changes in environment variable configuration and usage.
- Cleaned up package.json scripts to remove unnecessary preload references.

server.ts

@@ -21,9 +21,6 @@ import healthRouter from './src/routes/health';
 import { errorHandler } from './src/middleware/errorHandler';
 import { startBackgroundJobs } from './src/services/backgroundJobService';
 
-// Environment variables are now loaded by the `tsx` command in package.json scripts.
-// This ensures the correct .env file is used for development vs. testing.
-
 // --- START DEBUG LOGGING ---
 // Log the database connection details as seen by the SERVER PROCESS.
 // This will confirm if the `--env-file` flag is working as expected.
@@ -32,7 +29,7 @@ logger.info(`  NODE_ENV: ${process.env.NODE_ENV}`);
 logger.info(`  Host: ${process.env.DB_HOST}`);
 logger.info(`  Port: ${process.env.DB_PORT}`);
 logger.info(`  User: ${process.env.DB_USER}`);
-logger.info(`  Database: ${process.env.DB_DATABASE}`);
+logger.info(`  Database: ${process.env.DB_NAME}`);
 
 // Query the users table to see what the server process sees on startup.
 // Corrected the query to be unambiguous by specifying the table alias for each column.
@@ -101,8 +98,9 @@ const requestLogger = (req: Request, res: Response, next: NextFunction) => {
 app.use(requestLogger); // Use the logging middleware for all requests
 
 // --- Security Warning ---
-if ((process.env.JWT_SECRET || 'your_super_secret_jwt_key_change_this') === 'your_super_secret_jwt_key_change_this') {
-    logger.warn('Security Warning: JWT_SECRET is using a default, insecure value. Please set a strong secret in your .env file.');
+if (!process.env.JWT_SECRET) {
+    logger.error('CRITICAL: JWT_SECRET is not set. The application cannot start securely.');
+    process.exit(1);
 }
 
 // --- API Routes ---