v0.15.3

What's New

• JavaScript API: window.uiApp exposes the UIApp instance for programmatic access
• updateValue(elementId, value?): New method to update ui-value bindings from JavaScript
• getBinding(): New method to access the BindingEngine for widget lookup

Documentation

• Added JavaScript API section to USAGE.md
• New spec: specs/js-api.md
• Updated design docs with requirements R26-R31

Internal

• Refactored require() to delegate to DirectRequireLuaFile for code reuse