- provider_registry.py: ProviderRegistry (global + per-scope maps, lock,
generation counters, register/list/get/snapshot/restore/reset) with
export() binding the historical module-level names and _providers/
_scoped_providers/_lock test hooks into each *_registry module
- is_available_safe / configured_provider_name replace the 4 nested
_is_available_safe closures and 2 config-reading blocks
- browser/image_gen/video_gen/web_search/terminal_env/tts/transcription
registries keep their public API, log strings, error strings, builtin
collision policy (warn vs raise) and key normalization (strip vs lower)
Teknium