build: optimize public release binaries

[xjdr-noumena]

Summary

• Optimize public release binary build settings for production distribution.
• Keep the existing pure gh build contract and release workflow shape.

Local validation

• Built release binary locally.
• Ran smoke script locally.
• Ran package script locally.

Notes

• CI remains the merge gate for linux-x64, darwin-arm64, and darwin-x64 package smoke.