v0.44.0-alpha: fix prune_skills and orphan warning

Fixed

• ✓ No orphan skills — repo and hub are in sync. no longer fails with 'nothing to commit' — now correctly stages deletions via _prune_orphan_skills before committing
• share run auto-sync now warns about orphan skills instead of silently ignoring them
• Pre-existing callable | None type annotation crash on Python 3.14

Added

• Integration test for push() orphans warning contract
• Smoke tests for skills prune --dry-run and skills prune --yes
• prompts and themes entries to _stage_pi_extra_paths category_map (fixes stale install)