fix(ci): update to v1.2.0 and unify dirctl path across actions and wfs

[tkircsi]

Summary

• update CI workflows to use dirctl v1.2.0 and migrate Directory access from legacy GitHub token flags to the documented OIDC --auth-mode=oidc plus --auth-token flow
• unify dirctl binary handling across reusable actions and workflows by exposing setup-dirctl and build-dirctl output paths and passing dirctl_path through validation, push, publish, and sign actions
• update demo-dir and import-records workflows to fetch GitHub Actions OIDC tokens for Directory access while keeping Sigstore OIDC signing flow separate

Test plan

• run Demo - DIR with image_version=v1.2.0
• run Import MCP Records in dry-run mode against the public gateway
• verify push, publish, search, verify, and import commands succeed with OIDC auth and no --github-token usage

[github-actions]

The latest Buf updates on your PR. Results from workflow Buf CI / verify-proto (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	⏩ skipped	⏩ skipped	✅ passed	Apr 15, 2026, 11:19 AM