auto-claude: subtask-3-2 - Add rate limit feedback to ContactForm UI

- Added rate limit translations for en, de, and sr locales
- Added state to track remaining attempts from X-RateLimit-Remaining header
- Display warning when remaining attempts are low (<=2)
- Show user-friendly error messages with time until reset for 429 errors
- Added AlertTriangle icon for visual feedback on warnings
- All messages now use i18n translation keys for multilingual support

src/messages/en.json

@@ -411,7 +411,18 @@
         },
         "submit": "Send Message",
         "successMessage": "Thank you for your message! I will get back to you as soon as possible.",
-        "errorMessage": "Sorry, there was an error sending your message."
+        "errorMessage": "Sorry, there was an error sending your message.",
+        "rateLimit": {
+          "warning": "You have {count} {count, plural, one {attempt} other {attempts}} remaining",
+          "error": "Too many requests. Please try again in {time}.",
+          "blockedUntil": "Rate limit exceeded. You can try again in {time}."
+        },
+        "errors": {
+          "nameRequired": "Name is required",
+          "emailRequired": "Email is required",
+          "emailInvalid": "Please enter a valid email address",
+          "messageRequired": "Message is required"
+        }
       }
     },
     "privacy": {