fix: validate cross-compiled release binaries safely

[danielsuit]

Summary

• stop executing the ARM64 binary on an x86_64 GitHub runner
• validate ARM64 output with its ELF architecture instead
• add a manual exact-tag release retry path so v0.1.0 can be rebuilt without moving or deleting the tag
• explicitly bind GitHub Release publication to the requested tag

Failure addressed

Release run 33772482252 compiled and signed ARM64 successfully, then failed with Exec format error when the packaging step executed the cross-compiled binary. The x86_64 job passed; publication was correctly skipped.

Verification

• release workflow YAML parses
• git diff --check passes
• first release run confirms both cross-compiles succeed and isolates the failure to the host-architecture execution check

After merge, dispatch release.yml with tag=v0.1.0; no tag rewrite is needed.