- Create fileHandlerStore following ComfyUI's store patterns
- Move all handler registrations to coreFileHandlers.ts
- Clean up fileHandlers.ts to only contain implementations
- Update app.ts to use the new store-based system
- Remove duplicate isApiJson function
- Update tests for new architecture
This addresses review feedback about registration patterns while preserving the lazy evaluation fix for NaN parsing.
Restore lazy evaluation for metadata parsing to handle PNG files with NaN values in prompt field. Uses the original if-else loading logic to prevent parsing errors when workflow is valid but prompt contains invalid JSON.
Fixes#4199
