fix: remediate audited defects (resolves #29, #30, #31, #32)

- Fix permanent qBittorrent fallback degradation by resetting fallback flags during group-by polling (resolves #29)
- Fix Ombi webhook key mismatch in status endpoint and test mocks (resolves #30)
- Prevent timingSafeEqual TypeErrors on multi-byte CSRF token length mismatches (resolves #31)
- Eliminate duplicate write stream on server.log by delegating to index.js console override (resolves #32)

server/utils/logger.js

@@ -1,16 +1,7 @@
 // Copyright (c) 2026 Gordon Bolton. MIT License.
-const fs = require('fs');
-const path = require('path');
-
-// Use DATA_DIR so the non-root container user (UID 1000) can write logs.
-// Falls back to ../../data/server.log (same directory index.js uses).
-const DATA_DIR = process.env.DATA_DIR || path.join(__dirname, '../../data');
-if (!fs.existsSync(DATA_DIR)) fs.mkdirSync(DATA_DIR, { recursive: true });
-
-const logFile = fs.createWriteStream(path.join(DATA_DIR, 'server.log'), { flags: 'a' });
 
 function logToFile(message) {
-  logFile.write(`[${new Date().toISOString()}] ${message}\n`);
+  console.log(message);
 }
 
 module.exports = {