Merge remote-tracking branch 'origin/main' into refactor/codebase-cleanup

# Conflicts:
#	backend/src/routes/adminEvents.js
#	backend/src/routes/protectedImages.js
#	frontend/src/pages/admin/EventDetailsPage.tsx

backend/src/utils/rateLimitSecurity.js

@@ -32,7 +32,7 @@ function hasValidAdminToken(req) {
     
     // Critical: Verify token is valid before skipping rate limit
     // This prevents invalid tokens from bypassing rate limiting
-    const decoded = jwt.verify(token, process.env.JWT_SECRET);
+    const decoded = jwt.verify(token, process.env.JWT_SECRET, { algorithms: ['HS256'] });
     
     // Additional validation
     if (!decoded || typeof decoded !== 'object') {

backend/src/utils/timingSafe.js

@@ -0,0 +1,22 @@
+const crypto = require('crypto');
+
+/**
+ * Constant-time string comparison for secrets (share tokens, HMAC
+ * signatures, etc.). Returns false for non-strings or length mismatch
+ * without leaking timing beyond the (non-secret) length. Prevents an
+ * attacker from recovering a token byte-by-byte via response-time
+ * differences of a naive `a === b`.
+ */
+function timingSafeEqualStr(a, b) {
+  if (typeof a !== 'string' || typeof b !== 'string') {
+    return false;
+  }
+  const ab = Buffer.from(a);
+  const bb = Buffer.from(b);
+  if (ab.length !== bb.length) {
+    return false;
+  }
+  return crypto.timingSafeEqual(ab, bb);
+}
+
+module.exports = { timingSafeEqualStr };