Coordinated rename of the nine store-named bridge surfaces: Go
exports (InitExtensionStoreJSON -> InitExtensionRepoJSON etc.),
method-channel strings, the Kotlin and Swift handlers, and the Dart
PlatformBridge methods. Channel strings verified 1:1 across
Dart/Kotlin/Swift; gomobile bindings match the new export names.
Android MediaStore APIs untouched. store_registry_url pref key kept
for existing users. Local Android/iOS builds need the gobackend
AAR/xcframework rebuilt; CI does this in the release workflow.
store_provider.dart -> repo_provider.dart, screens/store/ ->
screens/repo/; Store* classes and storeProvider renamed to Repo*.
Method-channel names in platform_bridge stay unchanged (bridge ABI
matching the Kotlin handler).
zarzet