Related Issue

Closes #227

Motivation / Context

• Consumers may omit the license field or leave it empty in composer.json.
• The license generator previously passed that missing metadata into License\Resolver::resolve(), causing a TypeError before the command could skip generation cleanly.

Changes

• Allows the license resolver contract to receive missing or empty license metadata and return null.
• Keeps unsupported or absent license metadata on the existing skip path instead of failing.
• Adds regression coverage for missing, null, and empty license metadata without committing another consumer project fixture.

Verification

• composer dev-tools
• Focused command(s):
  • ./vendor/bin/phpunit tests/License/ResolverTest.php tests/License/GeneratorTest.php tests/Console/Command/LicenseCommandTest.php
  • composer dev-tools tests -- --filter='License' --no-cache
  • composer dev-tools code-style -- --json
  • composer dev-tools refactor -- --json
  • composer dev-tools phpdoc -- --json
  • composer dev-tools changelog:check
  • git diff --check
• Manual verification: created a temporary consumer fixture without license, ran composer install, then ran composer dev-tools license -- --dry-run --json; it skipped LICENSE generation cleanly without the previous TypeError. The temporary fixture was removed after the check.

composer dev-tools was also attempted, but this local shell still hits the existing nested process TTY failure (proc_open(/dev/tty): Failed to open stream: Device not configured) before the full gate can complete.

Documentation / Generated Output

• README updated
• docs/ updated
• Generated or synchronized output reviewed

No public docs or generated output changed; this is a defensive bug fix for missing metadata.

Changelog

• Added a notable CHANGELOG.md entry

Reviewer Notes

• The consumer-without-license case is covered permanently by unit tests; the full fixture project was intentionally not committed because this regression does not need another fixture tree.