feat(review): make review mode independent of tool selection

- Tool button clicks no longer exit review mode
- Review button moved outside tool group with divider separator
- Tool active state no longer dimmed during review mode
- Updated hint text for review mode

frontend/src/components/Toolbar.tsx

@@ -127,7 +127,7 @@ const toolButtons: { tool: ToolType; label: string; shortcut: string; numKey: st
   { tool: ToolType.TEXT, label: 'Text', shortcut: 'T', numKey: '4', Icon: IconText, hint: 'Click on the canvas to place text' },
 ];
 
-const REVIEW_HINT = 'Click an image to leave a comment. Press . to toggle.';
+const REVIEW_HINT = 'Click an object to place a comment pin. Press . to toggle.';
 
 export default function Toolbar({
   activeTool,
@@ -180,11 +180,11 @@ export default function Toolbar({
       {/* Tool buttons */}
       <div style={{ display: 'flex', gap: '1px', background: '#222', borderRadius: '8px', padding: '2px' }}>
         {toolButtons.map(({ tool, label, shortcut, numKey, Icon }) => {
-          const active = activeTool === tool && !reviewMode;
+          const active = activeTool === tool;
           return (
             <button
               key={tool}
-              onClick={() => { onToolChange(tool); if (reviewMode && onToggleReview) onToggleReview(); }}
+              onClick={() => onToolChange(tool)}
               title={`${label} (${shortcut} or ${numKey})`}
               style={{
                 display: 'flex', alignItems: 'center', justifyContent: 'center',
@@ -212,8 +212,10 @@ export default function Toolbar({
             </button>
           );
         })}
-        {/* Review mode — in tool group */}
-        {onToggleReview && (
+      </div>
+      {/* Review mode — independent toggle, separated from tools */}
+      {onToggleReview && (<>
+        <Divider />
         <button
           onClick={onToggleReview}
           title="Review (.)"
@@ -241,8 +243,7 @@ export default function Toolbar({
             .
           </span>
         </button>
-        )}
-      </div>
+      </>)}
 
       <Divider />