style(ai): widen model switcher label

Fits the resolved model name now shown on Default.

Author: abose

src/styles/Extn-AIChatPanel.less

@@ -149,7 +149,7 @@
         transition: opacity 0.5s ease;
 
         .ai-model-select-label {
-            max-width: 90px;
+            max-width: 120px; // model names are short; raw ids may ellipsize
             overflow: hidden;
             text-overflow: ellipsis;
             white-space: nowrap;