Autoplot 1.0.0

Initial direct-download release for macOS.

• Native macOS workspace for importing tabular data, assigning variables, analyzing plots, and composing export-ready figures.
• Includes X&Y plots, heat maps, correlation matrices, charts, 3D plotting, and Compose & Export workflows.
• Uses a sandboxed direct-download build with Sparkle updates and RevenueCat Web Billing.
• Supports Google and email sign-in in the direct build. Native Apple Sign-In is reserved for the future Mac App Store build.