🛡️ feat: Google Reverse Proxy support, CIVIC_INTEGRITY harm category

[KiGamji]

Summary

This PR implements reverse proxy support for Google endpoint, with the ability to pass the API key in Authorization header, as some reverse proxies don't properly handle x-goog-api-key. This is controlled by the GOOGLE_AUTH_HEADER variable, which defaults to false and is commented out by default. I have tested it, and it works perfectly fine, though it won't work with oai-reverse-proxy, as it is broken and passes some weird info data in chunks which makes the google-genai library crash. Further changes could include sanitization for chunks starting with ':', for anyone willing to implement proper support for this reverse proxy.

Change Type

Please delete any irrelevant options.

• New feature (non-breaking change which adds functionality)

[KiGamji]

it won't work with oai-reverse-proxy

also it gives this error, when the request gets sent from oai-reverse-proxy to the upstream API: "issues":"systemInstruction.role: Invalid enum value. Expected 'user' | 'model', received 'system'". pretty sure this comes from it's middleware. adding and setting it to 'user' from LibreChat seems to work, but that's a dirty solution too

[danny-avila]

Have you tested with Vertex AI and Gemini API?

[KiGamji]

Have you tested with Vertex AI and Gemini API?

Only Gemini API, shouldn't break Vertex AI though

[KiGamji]

the new request options are only set for GoogleGenerativeAI if created, and the Authorization header is toggleable in .env, being switched off by default.

[danny-avila]

this does break Vertex AI, will try to see if just adding what we had is fine

[danny-avila]

replaced by #5037