Token bucket rate limiter

[niteshpurohit]

Type: Task
Parent Issue: #423

Summary

Token bucket algorithm for smooth rate limiting with burst support and configurable refill rates

Scope

Token bucket algorithm for smooth rate limiting with burst support and configurable refill rates

Not In Scope

• Distributed rate limiting
• Redis-backed rate limiting

Acceptance Criteria

• token_bucket implements token bucket algorithm
• Burst support
• Configurable refill rates
• Tests verify rate limiting
• Documentation with algorithm explanation

C++ Native Library: No