chore(server): update config naming (#13419)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Updated scenario names and options for Copilot, including new and
renamed scenarios such as "audio_transcribing,"
"complex_text_generation," "quick_decision_making,"
"quick_text_generation," and "polish_and_summarize."
* Enhanced support for customizing and overriding default model
assignments in Copilot scenarios.

* **Bug Fixes**
* Improved consistency and clarity in scenario configuration and prompt
selection.

* **Documentation**
* Updated descriptions in configuration interfaces to better explain the
ability to use custom models and override defaults.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/embedding/client.ts

@@ -38,7 +38,7 @@ class ProductionEmbeddingClient extends EmbeddingClient {
 
   override async configured(): Promise<boolean> {
     const embedding = await this.providerFactory.getProvider({
-      modelId: this.config.copilot?.scenarios?.enabled
+      modelId: this.config.copilot?.scenarios?.override_enabled
         ? this.config.copilot.scenarios.scenarios?.embedding || EMBEDDING_MODEL
         : EMBEDDING_MODEL,
       outputType: ModelOutputType.Embedding,