fix(release): make registry publishing reproducible

[ZhiXiao-Lin]

Summary

• add crates.io-compatible project User-Agent headers and strict status handling
• wait for each crate to become visible before publishing its dependents
• add the required crates.io versions alongside pinned git revisions for a3s-acl and a3s-runtime
• add an exact-commit Action for publishing the pinned a3s-runtime prerequisite with the Box registry credential

Root causes addressed

The first v3.1.0 registry job stopped because crates.io rejects anonymous/default curl identification under its data-access policy. Publish dry-runs also exposed that the new a3s-runtime dependency was not yet on crates.io and that the pinned git dependencies lacked publishable version metadata.

Validation

• workflow YAML parsing
• changed embedded Bash blocks pass bash -n
• cargo metadata --locked --no-deps
• cargo publish --locked -p a3s-box-core --dry-run --allow-dirty
• cargo publish --locked -p a3s-box-netproxy --dry-run --allow-dirty
• crates.io API returns 200 with the project User-Agent
• pinned a3s-runtime source passes its own cargo publish --locked --dry-run