⚡ Bolt: Avoid strings.ToLower in proxy response header matching

[callmeradical]

💡 What: Replaced strings.HasPrefix(strings.ToLower(...), ...) with a zero-allocation prefix match using len(...) >= len(...) && strings.EqualFold(...).
🎯 Why: The original code used strings.ToLower in a hot path when proxying responses, which forced a memory allocation for every parsed HTTP response.
📊 Impact: Eliminates a memory allocation per proxy response, reducing garbage collection pressure and improving performance for high-throughput responses.
🔬 Measurement: Profiling heap allocations (go test -bench . -benchmem) will show a reduction in allocations per operation in the proxy loop.

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PR created automatically by Jules for task 6651251117106882050 started by @callmeradical

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