Implement Rate Limiting for Critical Endpoints

Ticket ID: SEC-RATELIMIT-001
Priority: High
Security Level: CRITICAL

**Feature Description**

Implement rate limiting on critical API endpoints to prevent abuse, brute force attacks, and ensure fair usage of platform resources. Protect authentication, registration, and data-intensive endpoints.

**Acceptance Criteria**

1. Protected Endpoints ✅

- High Priority (Strict Limits):

- POST /api/auth/login - 5 attempts per 15 minutes per IP

- POST /api/auth/register - 3 attempts per hour per IP

- POST /api/auth/forgot-password - 3 attempts per hour per IP

- POST /api/auth/reset-password - 5 attempts per hour per IP

- Medium Priority (Standard Limits):

- GET /api/metrics/dashboard - 30 requests per minute per user

- POST /api/projects - 10 creations per 30 minutes per user

- POST /api/events - 10 creations per 30 minutes per user

- POST /api/blogs - 5 creations per 30 minutes per user

- General Protection:

- All other authenticated endpoints: 100 requests per minute per user

- All public endpoints: 60 requests per minute per IP

2. Implementation Requirements ✅

- Use express-rate-limit middleware or another

- Redis store for distributed rate limiting (production)

- Memory store for testing

- Clear, consistent HTTP headers:
```
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 95
X-RateLimit-Reset: 1633039200
Retry-After: 60 (when blocked)
```

3. Response Format ✅
```
json

{
"error": "Too Many Requests",
"message": "Rate limit exceeded. Please try again in 60 seconds.",
"retryAfter": 60,
"timestamp": "2024-01-15T10:30:00Z"
}
```

`Status Code: 429 Too Many Requests`

4. Configuration ✅

Environment-based configuration:
```
env

RATE_LIMIT_ENABLED=true
RATE_LIMIT_WINDOW_MS=60000
RATE_LIMIT_MAX_REQUESTS=100
```

- Different limits for development/production

- Ability to disable for specific routes (webhooks, health checks)

5. Skip List ✅

- Exclude from rate limiting:

- GET /api/health - Health checks

- GET /api/docs - API documentation

- Internal webhook endpoints (specify which)

6. Monitoring & Logging ✅

- Log rate limit hits with context (user, endpoint, IP)

- Send alert on sustained rate limit violations (>10 blocks in 5min)

- Metrics exposed: rate_limit_hits_total, rate_limit_blocks_total

- Admin endpoint to view current rate limit status: GET /api/admin/rate-limits/status

8. Documentation ✅

- Create a security docs folder and draft a detailed rate_limit.md file explaining the overall strategy

9. Testing ✅

- Unit tests for rate limit middleware

- Integration tests verifying limits work correctly