plum v0.4.0

Changelog

• 63984da Initial planning of plugin manager cli
• ffae1cd feat: add Cobra CLI Framework (Phase 1)
• a6fbe8c feat: add CLI advanced commands (Phase 4)
• 4673aea feat: add CLI commands (Phase 1 + Phase 2)
• 47dfb82 feat: add CLI write commands (Phase 3)
• 0211065 feat: add automatic backup and safety documentation
• c65b8c9 feat: add marketplace refresh command with security fixes
• 38d0ff4 fix(critical): preserve all settings.json fields when modifying plugins
• d7e292c fix(security): address code review issues in Phase 3
• 25face1 fix(settings): address code review issues
• 5adeb20 fix: add Windows support for file locking
• 1277051 fix: deduplicate plugins by name across all sources