[httpdss]

Problem

structkit v3.3.0 renamed the default project file from .struct.yaml to .structkit.yaml. The CLI generate command prefers .structkit.yaml and falls back to .struct.yaml, but validate / vars / lint take an explicit path with no fallback.

This action still defaulted struct_file to .struct.yaml and runs validate by default, so repos that only have .structkit.yaml failed.

Solution

When struct_file is empty or unset, auto-detect the config file:

1. Use .structkit.yaml if it exists
2. Otherwise use legacy .struct.yaml
3. Otherwise fail with a clear error that names both files and the struct_file input

Explicit struct_file values are passed through unchanged.

Also in this PR

• Document auto-detect and the legacy .struct.yaml fallback in action.yml and the README
• Note that no_hooks requires structkit >= 3.3.0
• Point examples and CI at .structkit.yaml
• Add fixtures and workflow jobs covering both file names, auto-detect, preference when both exist, and a missing-file error
• Version tag / release-drafter / major tagging references are left as they are

Testing

• Local: tests/resolve-struct-file.test.sh
• Local: structkit validate (3.3.0) on both fixtures
• GitHub Actions: expanded .github/workflows/test.yml jobs