fix(review): import shared type and apply setup choice to active diff

Import DefaultDiffType from @plannotator/shared/config instead of
duplicating the type locally. Pass the selected diff type back through
onComplete so the current review switches immediately when the user
picks a different default.

For provenance purposes, this commit was AI assisted.

Author: backnotprop

packages/review-editor/App.tsx

@@ -1928,7 +1928,10 @@ const ReviewApp: React.FC = () => {
         {/* Diff type setup dialog — first-run only */}
         {showDiffTypeSetup && (
           <DiffTypeSetupDialog
-            onComplete={() => setShowDiffTypeSetup(false)}
+            onComplete={(selected) => {
+              setShowDiffTypeSetup(false);
+              if (selected !== diffType) handleDiffSwitch(selected);
+            }}
           />
         )}
 

packages/ui/components/DiffTypeSetupDialog.tsx

@@ -1,10 +1,9 @@
 import React, { useState } from 'react';
 import { createPortal } from 'react-dom';
+import type { DefaultDiffType } from '@plannotator/shared/config';
 import { markDiffTypeSetupDone } from '../utils/diffTypeSetup';
 import { configStore } from '../config';
 
-type DefaultDiffType = 'uncommitted' | 'unstaged' | 'staged';
-
 const OPTIONS: { value: DefaultDiffType; label: string; description: string }[] = [
   {
     value: 'unstaged',
@@ -24,20 +23,20 @@ const OPTIONS: { value: DefaultDiffType; label: string; description: string }[]
 ];
 
 interface DiffTypeSetupDialogProps {
-  onComplete: () => void;
+  onComplete: (selected: DefaultDiffType) => void;
 }
 
 export const DiffTypeSetupDialog: React.FC<DiffTypeSetupDialogProps> = ({
   onComplete,
 }) => {
   const [selected, setSelected] = useState<DefaultDiffType>(
-    () => configStore.get('defaultDiffType') as DefaultDiffType
+    () => configStore.get('defaultDiffType')
   );
 
   const handleDone = () => {
     configStore.set('defaultDiffType', selected);
     markDiffTypeSetupDone();
-    onComplete();
+    onComplete(selected);
   };
 
   return createPortal(