⚡ Bolt: Avoid strings.ToLower allocation in proxy HTTP header matching

[callmeradical]

💡 What: Replaced strings.ToLower in combination with strings.HasPrefix with a zero-allocation approach using strings.EqualFold and slicing for matching the text/event-stream header in the proxy.
🎯 Why: strings.ToLower forces a memory allocation and creates garbage collection pressure in hot paths (like processing HTTP responses in the proxy).
📊 Impact: Eliminates a memory allocation per proxy HTTP response containing a text/event-stream or similar content type header, reducing GC pressure and marginally improving throughput.
🔬 Measurement: Verified correctness by running go test ./... to ensure header matching semantics remain identical.

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PR created automatically by Jules for task 13362341045440475811 started by @callmeradical

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