[BUG] No Rate Limiting on AI & GitHub API Endpoints #66

Bug Description

What is the problem?

Currently, there is no rate limiting on AI-powered and GitHub-based API endpoints.
This allows users to send unlimited requests in a short time.

Steps to Reproduce

1. Send repeated requests to AI-powered endpoints
2. Continuously hit GitHub API–based endpoints
3. Observe there is no restriction or cooldown applied

Expected Behavior

The backend should:

• Limit the number of requests per user
• Prevent API abuse
• Protect external API quotas

Actual Behavior

Users can spam requests without limits, which can:

• Exhaust GitHub and AI API quotas
• Increase backend load
• Affect other users

Component

Backend

Environment

Backend (FastAPI middleware, API layer)
Backend service (environment-independent)

Additional Context

This can be implemented using FastAPI middleware with per-user rate limiting.
I’d like to work on this issue as part of SWoC — please assign it to me if it aligns with the project roadmap.