Factory Units and Upgrades

[1brucben]

This pull request introduces support for building "Factory" structures with customizable default levels, similar to other upgradeable buildings. It adds the Factory to the build menu, keybinds, localization, and settings, and ensures that build costs and levels are correctly handled and persisted. The changes also introduce a new modal for managing default build levels for upgradeable structures, with persistent local storage and UI integration.

Factory structure support & build menu enhancements:

• Added Factory as a buildable structure throughout the UI, including the build menu (BuildMenu.ts), keybinds, and localization files, with corresponding icons and descriptions. [1] [2] [3] [4] [5] [6] [7]
• Updated build cost calculations for upgradeable structures to use the desired starting level from persistent local settings, including Factory. [1] [2] [3] [4]

Keybind and user settings integration:

• Added new keybinds for building Factory and Research Lab, with user settings support and default keys (KeyF and KeyL). [1] [2] [3] [4] [5]

Build settings modal:

• Introduced a new BuildSettingsModal component to allow users to set default build levels for upgradeable structures, with persistent storage and UI controls. [1] [2]

General improvements:

• Updated build cost multipliers and initial levels for Factory in relevant configuration objects. [1] [2]
• Ensured correct handling of build intents and local storage for structure levels in the transport logic. [1] [2]

These changes collectively add a new upgradeable building type and improve the user experience for customizing build defaults and costs.