defaultFlutterGemmaInstance function
Web default for FlutterGemmaPlugin — never actually used at runtime.
On web, FlutterGemmaWeb registers itself as FlutterGemmaPlugin.instance
during plugin registration, so this default is overwritten before any call.
It exists only so the web/wasm compile graph doesn't pull in
FlutterGemmaMobile (and its dart:io).
Implementation
FlutterGemmaPlugin defaultFlutterGemmaInstance() => throw UnsupportedError(
'No default FlutterGemmaPlugin on web — FlutterGemmaWeb must register '
'itself as the platform instance during plugin registration.',
);