chore: update release notes and version to 1.6.0-beta.5

- Enhanced web search functionality and optimized knowledge base settings for better performance.
- Added automatic image generation for Gemini 2.5 Flash Image model and improved OCR service compatibility on Linux.
- Refactored AI core architecture and improved message retry mechanisms.
- Fixed various UI component issues and improved overall stability.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "CherryStudio",
-  "version": "1.6.0-beta.4",
+  "version": "1.6.0-beta.5",
   "private": true,
   "description": "A powerful AI assistant for producer.",
   "main": "./out/main/index.js",