feat(tui): refactor TUI components for improved text rendering and styling

- Removed unused escape_markup function and integrated rich.text for better text handling.
- Updated various renderers to utilize Text for consistent styling and formatting.
- Enhanced chat and agent message displays with dynamic text features.
- Improved error handling and display for various tool components.
- Refined TUI styles for better visual consistency across components.

strix/interface/assets/tui_styles.tcss

@@ -48,7 +48,7 @@ Screen {
 #agents_tree {
     height: 1fr;
     background: transparent;
-    border: round #1a1a1a;
+    border: round #333333;
     border-title-color: #a8a29e;
     border-title-style: bold;
     padding: 1;