🔄 Add In-App Update Checker with Universal macOS Support

• Added automatic update detection on app startup
• Created update popup notifications for new releases
• Implemented one-click downloads from GitHub releases
• Added manual update checking in Settings
• Universal macOS DMG support (Intel + Apple Silicon)
• Simplified download naming (BeautifyOllama.dmg)
• Cross-platform support (macOS, Windows, Linux)
• Smart download priority for universal binaries
• Version updated to 1.7.0 across all configs