feat(server): migrate copilot to native (#14620)

#### PR Dependency Tree


* **PR #14620** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

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

* **New Features**
* Native LLM workflows: structured outputs, embeddings, and reranking
plus richer multimodal attachments (images, audio, files) and improved
remote-attachment inlining.

* **Refactor**
* Tooling API unified behind a local tool-definition helper;
provider/adapters reorganized to route through native dispatch paths.

* **Chores**
* Dependency updates, removed legacy Google SDK integrations, and
increased front memory allocation.

* **Tests**
* Expanded end-to-end and streaming tests exercising native provider
flows, attachments, and rerank/structured scenarios.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/transcript/service.ts

@@ -224,11 +224,10 @@ export class CopilotTranscriptionService {
     const config = Object.assign({}, prompt.config);
     if (schema) {
       const provider = await this.getProvider(prompt.model, true, prefer);
-      return provider.structure(
-        cond,
-        [...prompt.finish({ schema }), msg],
-        config
-      );
+      return provider.structure(cond, [...prompt.finish({}), msg], {
+        ...config,
+        schema,
+      });
     } else {
       const provider = await this.getProvider(prompt.model, false);
       return provider.text(cond, [...prompt.finish({}), msg], config);