WizardLayout: fix gap between nav and sticky search on scroll

- Removed top padding from list-map scroll container (pt: 0)
- Back link gets its own pt: 1.5 wrapper for breathing room
- Sticky search bar now pins flush against nav when scrolled

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

src/components/templates/WizardLayout/WizardLayout.tsx

@@ -177,7 +177,8 @@ const ListMapLayout: React.FC<{
         flexShrink: 0,
         overflowY: 'auto',
         px: { xs: 2, md: 3 },
-        py: 3,
+        pt: 0,
+        pb: 3,
         // Thin scrollbar, hidden until hover
         scrollbarWidth: 'thin',
         scrollbarColor: 'transparent transparent',
@@ -376,7 +377,9 @@ export const WizardLayout = React.forwardRef<HTMLDivElement, WizardLayoutProps>(
             secondaryPanel={secondaryPanel}
             backLink={
               showBackLink && variant === 'list-map' ? (
+                <Box sx={{ pt: 1.5 }}>
                   <BackLink label={backLabel} onClick={onBack} />
+                </Box>
               ) : undefined
             }
           >