feat: Implement path and tag filtering

[juan-rojas-affirm]

Aims to resolve #64.

Adds pathFilter setting and makes releaseTagNameFormat bidirectional
to support independent versioning of subprojects in a monorepo.

pathFilter

When set, only commits touching that directory count toward version bumps and changelog.

• Uses JGit PathFilter + ANY_DIFF so tree comparisons are correct.
• Commits outside the filter are still traversed (so release tags in their ancestry are found), but:
  • marked as ignored
  • skipped during version accumulation

releaseTagNameFormat as read filter

The static prefix before %s (e.g. "lib-v" from "lib-v%s") is used to filter which tags are read.

• Prevents cross-subproject tag pollution.

Bounded filter RevWalk

The path-filter pre-scan stops at the last version boundary (tagged commits + release-message commits) instead of walking the full history.

• getTags() is computed once and shared between:
  • VersionFinder
  • getHeadCommit

[jmongard]

Thank you for implementing the feature :-)