WizardLayout: lock list-map to viewport for independent panel scroll

- list-map variant now uses height: 100vh + overflow: hidden on outer wrapper
- Only the left panel scrolls (overflowY: auto already set)
- Map panel stays fixed, help bar pins to bottom
- Added minHeight: 0 on main element to prevent flex overflow
- Other layout variants unchanged (still use minHeight: 100vh)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/templates/WizardLayout/WizardLayout.tsx

@@ -342,6 +342,11 @@ export const WizardLayout = React.forwardRef<HTMLDivElement, WizardLayoutProps>(
             flexDirection: 'column',
             minHeight: '100vh',
             bgcolor: 'background.default',
+            // list-map: lock to viewport so only the left panel scrolls
+            ...(variant === 'list-map' && {
+              height: '100vh',
+              overflow: 'hidden',
+            }),
           },
           ...(Array.isArray(sx) ? sx : [sx]),
         ]}
@@ -363,7 +368,10 @@ export const WizardLayout = React.forwardRef<HTMLDivElement, WizardLayoutProps>(
         )}
 
         {/* Main content area */}
-        <Box component="main" sx={{ display: 'flex', flexDirection: 'column', flex: 1 }}>
+        <Box
+          component="main"
+          sx={{ display: 'flex', flexDirection: 'column', flex: 1, minHeight: 0 }}
+        >
           <LayoutComponent
             secondaryPanel={secondaryPanel}
             backLink={