Extract core system modules from monolithic index.js into modular architecture:
- src/core/state.js: All extension state variables with controlled setters
- src/core/persistence.js: Settings and chat data persistence functions
- src/core/config.js: Extension metadata and default configuration
- src/core/events.js: SillyTavern event system wrapper
Updated index.js to import and use new core modules.
Removed ~220 lines of state/persistence code from index.js.
Part of Epic 1: Foundation & Core Systems (Phase 1.1-1.2)
Lucas 'Paperboy' Rose-Winters