fix: multiple UI and API issues

- Fix tool calls format for DeepSeek API (add type field)

- Fix config event handler name

- Fix message history display (preserve all messages)

- Fix right panel width and scrolling

- Add async config update to prevent UI freeze

- Add prompt caching with singleton pattern

- Update build scripts with complete hidden imports

ui/styles/app.css

@@ -22,15 +22,14 @@ LeftPanel {
 }
 
 RightPanel {
-    width: 70;
+    width: 35;
     dock: right;
     background: $panel;
-    overflow-y: auto;
 }
 
 RightPanel ScrollableContainer {
-    height: 1fr;
-    overflow-y: auto;
+    height: 100%;
+    overflow-y: scroll;
 }
 
 StatusBar {