v0.3.0

Changes

• Added --json output for patch, commit, apply, undo, status, and doctor.
• Rejected same-package dependency_overrides from project pubspec.yaml files before patch or apply mutates Patchwork state.
• Derived historical patch inventory from durable patches/*.patch files while keeping current patch ownership in patchwork.lock.

Published to pub.dev as patchwork 0.3.0.