feat(server): converge legacy compatibility (#15426)

#### PR Dependency Tree


* **PR #15426** 👈

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**
* Added workspace BYOK profiles with provider/model catalogs, capability
validation, connection probing, credential rotation, reordering, and
secure local leases.
* Added Copilot route options, selectable targets, managed tiers,
explicit profile/model overrides, and improved streaming with tool
callbacks and abort support.
* Added Copilot availability controls to prevent access when the feature
is disabled.
* **Changes**
* Simplified Copilot configuration and removed legacy provider-specific
settings.
* Removed obsolete model, token-cost, transcript strategy, and provider
metadata fields from public responses.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

tests/kit/src/utils/cloud.ts

@@ -155,21 +155,6 @@ export async function cleanupWorkspace(workspaceId: string): Promise<void> {
   });
 }
 
-export async function switchDefaultChatModel(model: string) {
-  await runPrisma(async client => {
-    const prompt = await client.aiPrompt.findFirst({
-      where: { name: 'Chat With AFFiNE AI' },
-      select: { id: true },
-    });
-    if (!prompt) return;
-
-    await client.aiPrompt.update({
-      where: { id: prompt.id },
-      data: { model },
-    });
-  });
-}
-
 export async function createRandomAIUser(): Promise<{
   name: string;
   email: string;