Enable ESLint no-unused-vars rule (#4367)

# Description of Changes
Enable ESLint [no-unused-vars
rule](https://typescript-eslint.io/rules/no-unused-vars/)

frontend/src/components/shared/quickAccessBar/ActiveToolButton.tsx

@@ -1,10 +1,10 @@
 /**
  * ActiveToolButton - Shows the currently selected tool at the top of the Quick Access Bar
- * 
+ *
  * When a user selects a tool from the All Tools list, this component displays the tool's
  * icon and name at the top of the navigation bar. It provides a quick way to see which
  * tool is currently active and offers a back button to return to the All Tools list.
- * 
+ *
  * Features:
  * - Shows tool icon and name when a tool is selected
  * - Hover to reveal back arrow for returning to All Tools
@@ -26,7 +26,7 @@ interface ActiveToolButtonProps {
 
 const NAV_IDS = ['read', 'sign', 'automate'];
 
-const ActiveToolButton: React.FC<ActiveToolButtonProps> = ({ activeButton, setActiveButton }) => {
+const ActiveToolButton: React.FC<ActiveToolButtonProps> = ({ setActiveButton }) => {
   const { selectedTool, selectedToolKey, leftPanelView, handleBackToTools } = useToolWorkflow();
 
   // Determine if the indicator should be visible (do not require selectedTool to be resolved yet)
@@ -38,7 +38,6 @@ const ActiveToolButton: React.FC<ActiveToolButtonProps> = ({ activeButton, setAc
   const [indicatorTool, setIndicatorTool] = useState<typeof selectedTool | null>(null);
   const [indicatorVisible, setIndicatorVisible] = useState<boolean>(false);
   const [replayAnim, setReplayAnim] = useState<boolean>(false);
-  const [isAnimating, setIsAnimating] = useState<boolean>(false);
   const [isBackHover, setIsBackHover] = useState<boolean>(false);
   const prevKeyRef = useRef<string | null>(null);
   const collapseTimeoutRef = useRef<number | null>(null);
@@ -71,11 +70,9 @@ const ActiveToolButton: React.FC<ActiveToolButtonProps> = ({ activeButton, setAc
     replayRafRef.current = requestAnimationFrame(() => {
       setReplayAnim(true);
     });
-    setIsAnimating(true);
     prevKeyRef.current = (selectedToolKey as string) || null;
     animTimeoutRef.current = window.setTimeout(() => {
       setReplayAnim(false);
-      setIsAnimating(false);
       animTimeoutRef.current = null;
     }, 500);
   }
@@ -84,10 +81,8 @@ const ActiveToolButton: React.FC<ActiveToolButtonProps> = ({ activeButton, setAc
     clearTimers();
     setIndicatorTool(selectedTool);
     setIndicatorVisible(true);
-    setIsAnimating(true);
     prevKeyRef.current = (selectedToolKey as string) || null;
     animTimeoutRef.current = window.setTimeout(() => {
-      setIsAnimating(false);
       animTimeoutRef.current = null;
     }, 500);
   }
@@ -95,11 +90,9 @@ const ActiveToolButton: React.FC<ActiveToolButtonProps> = ({ activeButton, setAc
   const triggerCollapse = () => {
     clearTimers();
     setIndicatorVisible(false);
-    setIsAnimating(true);
     collapseTimeoutRef.current = window.setTimeout(() => {
       setIndicatorTool(null);
       prevKeyRef.current = null;
-      setIsAnimating(false);
       collapseTimeoutRef.current = null;
     }, 500); // match CSS transition duration
   }