Update tests and workflows: align CI/Release with offline-only valida…

[jecacs]

…tion, document manual integration test options, and simplify release gates.

Summary

Describe the problem, the chosen solution, and any compatibility or API impact.

Validation

• I added or updated deterministic tests for changed behavior.
• I ran the relevant Release build/tests and the formatting check.
• Crypto, wire-format, and program-layout changes include an upstream or independent compatibility vector.
• Untrusted-input bounds, allocation behavior, secret handling, and exception/log content were reviewed.
• Public API XML docs and relevant README/usage/changelog documentation are updated.
• Dependency changes include the affected lock files; workflow actions remain pinned to full commit SHAs.
• This change does not contain private keys, credentials, generated build output, or unrelated edits.

References

Link the issue, upstream source revision, specification, or advisory used to validate the change.