feat: add group name functionality to models

- Introduced a new `group_name` field in the model configuration to allow for custom provider-group display names.
- Updated the `CursorModelCards`, `CursorModelEditor`, and `CursorSettingsPage` components to support group settings.
- Enhanced the UI to include group settings options, allowing users to modify group names and associated configurations.
- Added localization strings for new group settings features in both English and Chinese.
- Implemented a database migration to add the `group_name` column to the model configurations.

server/migrations/0008_add_model_group_name.sql

@@ -0,0 +1,4 @@
+-- Custom provider-group display name shared by models with the same upstream host.
+-- NULL means no custom name; the UI falls back to the base_url hostname and the
+-- Cursor model picker badge falls back to the model type label.
+ALTER TABLE model_configs ADD COLUMN group_name TEXT;