Remove the ANTHROPIC_OAUTH provider type, anthropic_oauth_provider,
AnthropicOAuthWorker, and all associated UI authentication flows
from settings_controller. Update provider_types, factory, message
format adapter mapping, and migration maps accordingly.
Add qt_compat.py shim that tries PySide6 first, falls back to PyQt5,
and re-exports all Qt classes under unified names. Replace all direct
PySide6 imports across 22 files with qt_compat imports. Normalize
scoped enums to flat enums for PyQt5 compatibility, replace .exec()
with exec_dialog() wrapper, and fix QTimeZone.utc() portability.
Bump version to 1.2.0 and add IDA 9.1 to supported versions.
Jason Tang