feat(server): update claude models (#13677)

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

* **New Features**
* Copilot now defaults to the updated Claude Sonnet 4.5 model across
experiences for improved responses.

* **Chores**
* Consolidated available Anthropic models, removing older Sonnet 3.x
variants and standardizing Sonnet 4/4.5 options.
* Updated configuration defaults and schema mappings to reference the
new Sonnet 4.5 model.

* **Tests**
* Updated unit and end-to-end tests to reference the new model to ensure
consistent behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

tests/affine-local/e2e/blocksuite/clipboard/clipboard.spec.ts

@@ -386,7 +386,7 @@ test.describe('paste to code block', () => {
     await pressEnter(page);
     await addCodeBlock(page);
     const plainTextCode = [
-      '  model: anthropic("claude-3-7-sonnet-20250219"),',
+      '  model: anthropic("claude-sonnet-4-5-20250929"),',
       '  prompt: How many people will live in the world in 2040?',
       '  providerOptions: {',
       '    anthropic: {',