[fix] restore the existing Go floor and interpreter baseline

[vt128]

Restore the existing Go 1.25.8 source-build floor and the ecosystem's fixed Starlark interpreter, ffb3f39dd27a, before the next release. Keep the entrypoint, permissions, recording, packaging, networking and Unicode fixes already merged.

x/crypto v0.55.0 supports Go 1.25; its SHA-3 package is used by request validation. The later v0.56.0 increase was needed for SSH fixes, while this CLI imports neither SSH nor OpenPGP. Their known module advisories remain disclosed, and CI now rejects introducing either package without another dependency review. The parser recursion limitation of the fixed Starlark baseline is documented in the packaged SECURITY.md; this release no longer claims to fix it. Production artifacts still use Go 1.27.1.

The examples module and CI floor follow the restored requirement. A selected-module check prevents transitive interpreter drift.

Validation: local build, full race tests twice, vet and formatting passed; Linux amd64 Go 1.25.8 build, race tests twice and vet passed. Network/Unicode findings stay resolved in the source scan; module-only advisories and the separately known parser risk are recorded rather than suppressed. The existing six native install/upgrade/rollback and container CI gates remain required.

Refs STAR-112. No tag or release is created.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.99%. Comparing base (593bc5f) to head (7032a82).

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #39   +/-   ##
=======================================
  Coverage   87.99%   87.99%           
=======================================
  Files          23       23           
  Lines        1166     1166           
=======================================
  Hits         1026     1026           
  Misses        108      108           
  Partials       32       32           

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