fix(backend/store): bound split_camelcase input to prevent ReDoS

Add a 500-character input length limit to split_camelcase() to address
CodeQL polynomial regex warning on uncontrolled data.

autogpt_platform/backend/backend/api/features/store/text_utils.py

@@ -13,6 +13,7 @@ def split_camelcase(text: str) -> str:
         >>> split_camelcase("HTTPRequestBlock")
         'HTTP Request Block'
     """
+    text = text[:500]  # Bound input length to prevent regex DoS
     text = re.sub(r"([a-z0-9])([A-Z])", r"\1 \2", text)
     text = re.sub(r"([A-Z]+)([A-Z][a-z])", r"\1 \2", text)
     return text