fix(terminal): improve tab bar font size and contrast

Bump font size from 11px to 12px for tab items, icons, cwd, and
action buttons. Use active text color for better readability in
both light and dark themes. Increase cwd opacity from 0.6 to 0.8.

Author: abose

src/styles/Extn-Terminal.less

@@ -153,8 +153,8 @@
     height: 28px;
     min-height: 28px;
     cursor: pointer;
-    color: var(--terminal-tab-text);
-    font-size: 11px;
+    color: var(--terminal-tab-active-text);
+    font-size: 12px;
     white-space: nowrap;
     overflow: hidden;
 }
@@ -176,7 +176,7 @@
     display: flex;
     align-items: center;
     justify-content: center;
-    font-size: 11px;
+    font-size: 12px;
     flex-shrink: 0;
 }
 
@@ -190,14 +190,14 @@
 }
 
 .terminal-flyout-cwd {
-    font-size: 11px;
+    font-size: 12px;
     color: var(--terminal-tab-text);
     flex-shrink: 1;
     min-width: 0;
     max-width: 50%;
     margin-left: 4px;
     margin-right: 2px;
-    opacity: 0.6;
+    opacity: 0.8;
     overflow: hidden;
     text-overflow: ellipsis;
     display: none;
@@ -265,8 +265,8 @@
     height: 100%;
     padding: 0;
     cursor: pointer;
-    color: var(--terminal-tab-text);
-    font-size: 11px;
+    color: var(--terminal-tab-active-text);
+    font-size: 12px;
     background: transparent;
     border: none;
     overflow: hidden;
@@ -275,7 +275,6 @@
 
 .terminal-flyout-new-btn:hover {
     background: rgba(255, 255, 255, 0.05);
-    color: var(--terminal-tab-active-text);
 }
 
 /* Dropdown chevron: visible in both modes */