Implement API Usage Analytics

[Shredder401k]

Type: Feature
Priority: Medium
Labels: feature, backend, analytics

Description:
Add analytics dashboard for API usage patterns.

Metrics to Track:

• Request volume
• Response times
• Error rates
• Endpoint popularity
• User patterns
• Rate limit hits

Acceptance Criteria:

• Analytics dashboard functional
• Real-time metrics
• Historical data retained
• All CI/CD checks must pass

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