• docs: add GitHub Release version badge [skip ci]
• docs: add AndroidFreeware download badge [skip ci]
• docs: add F-Droid and OpenAPK download badges [skip ci]
• feat: AI target recommendations evaluate current targets before suggesting changes
• fix: preserve user data on app update (Room migration safety)
• feat: configurable day-start hour in Settings
• feat: replace ZXing Java with zxing-cpp for barcode scanning
• feat: solar system orbit animation math with property tests
