⚡ Bolt: Optimize TokenBucketLimiter refill allocation

[google-labs-jules]

⚡ Bolt: Optimized TokenBucketLimiter refill

💡 What:

• Replaced AtomicInteger.updateAndGet with a manual compareAndSet loop in TokenBucketLimiter.refill().
• Added overflow protection for periodsElapsed * refillTokens.
• Added overflow protection for current + tokensToAdd using long arithmetic.

🎯 Why:

• The updateAndGet method allocates a lambda object on every successful refill, creating unnecessary GC pressure in high-throughput scenarios.
• The original code was susceptible to integer overflow if periodsElapsed was very large (long sleep/suspend) or if the bucket was near capacity.

📊 Impact:

• Zero object allocation during token refill.
• Correct handling of potential integer overflows.

🔬 Measurement:

• Verified with existing test suite (./gradlew test), specifically testThreadSafety which hammers the limiter concurrently.

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PR created automatically by Jules for task 51746987566456691 started by @SpaceLeam

[google-labs-jules]

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