feat(core): add o4-mini model (#12175)

Close [AI-85](https://linear.app/affine-design/issue/AI-85)

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

- **New Features**
	- Enhanced AI chat experience with improved web search integration, including a new "AUTO" mode that allows the AI to search the web only when needed.
	- Updated AI model for chat to "o4-mini" for improved performance.
- **Improvements**
	- Refined instructions to reduce hallucinations and ensure the AI admits uncertainty when unsure.
	- Enhanced streaming responses to display web search queries and results more clearly.
	- Updated web search tool modes for more accurate and flexible search behavior.
	- Centralized AI provider options and improved tool selection logic for better response quality.
- **Bug Fixes**
	- Improved handling of tool calls and reasoning steps in AI chat responses.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/package.json

@@ -29,7 +29,7 @@
     "@affine/server-native": "workspace:*",
     "@ai-sdk/anthropic": "^1.2.10",
     "@ai-sdk/google": "^1.2.10",
-    "@ai-sdk/openai": "^1.3.18",
+    "@ai-sdk/openai": "^1.3.21",
     "@ai-sdk/perplexity": "^1.1.6",
     "@apollo/server": "^4.11.3",
     "@aws-sdk/client-s3": "^3.779.0",