Bundle Go dependency license files

[timkpaine]

Description

Add opt-in Go dependency license bundles using go-licenses save .. CI installs the tested collector, google/go-licenses v2.0.1; users install it separately.

• Configure licenses.destination as a wheel-relative directory. Preserve every original saved license, notice, and source artifact in standard and editable wheels; keep temporary output out of source distributions.
• Match the build's target, CGO configuration, effective GOFLAGS, and explicit package-selection flags. Reject shell-dependent flags and disable external package drivers for collection.
• Fail on missing or unknown licenses, collector errors, empty license texts, symlinks, unsafe paths, destination collisions, and Hatch source rewrites.
• Document collection limits and review requirements. Some classifications save whole source directories, potentially including unrelated local files. Standard-library/runtime licenses and dependencies hidden in C/C++, assembly, or system libraries need separate review.

Verified on macOS arm64 with Python 3.12.14 and Go 1.27.1: 87 source tests and all 87 tests from the installed plugin wheel, 95.25% coverage, lint, type checks, manifest checks, wheel/sdist builds, and Twine checks. Tests cover real direct/transitive and build-tag-selected dependencies, persisted Go configuration, CRLF notices, full reciprocal-license source trees, native imports, standard/editable wheels, and sdist-to-wheel builds.

Runtime dependencies and version remain unchanged. editables is added only to the development extra for Hatchling's editable-wheel tests. No release is included.

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor / code cleanup
• CI / build configuration
• Other (describe below)

Checklist

• Linting passes (make lint)
• Tests pass (make test; run through make coverage)
• New tests added for new functionality
• Documentation updated (if applicable)
• Changelog / version bump (if applicable; not requested)

[github-actions]

Test Results

87 tests  +62   87 ✅ +62   42s ⏱️ +33s
 1 suites ± 0    0 💤 ± 0 
 1 files   ± 0    0 ❌ ± 0 

Results for commit d3629f8. ± Comparison against base commit 280a888.

[codecov]

Codecov Report

❌ Patch coverage is 95.05376% with 23 lines in your changes missing coverage. Please review.
✅ Project coverage is 95.24%. Comparing base (280a888) to head (d3629f8).

Files with missing lines	Patch %	Lines
hatch_go/plugin.py	78.26%	15 Missing ⚠️
hatch_go/licenses.py	89.61%	8 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #36       +/-   ##
===========================================
+ Coverage   78.14%   95.24%   +17.10%     
===========================================
  Files           8       12        +4     
  Lines         421      884      +463     
===========================================
+ Hits          329      842      +513     
+ Misses         92       42       -50     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.