fix: resolve all MUI v9 TypeScript build errors

- Move system props (fontWeight, lineHeight, display, alignItems, etc.) into sx
- Fix Lucide icon color prop (no sx support)
- Merge duplicate sx attributes
- Remove unused variables (location, _needId, v)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/demand/Shortlists.tsx

@@ -62,7 +62,7 @@ export default function Shortlists() {
         }}
       >
         <Box>
-          <Typography variant="h5" fontWeight={700} color="text.primary">
+          <Typography variant="h5" sx={{ fontWeight: 700 }} color="text.primary">
             Shortlists
           </Typography>
           <Typography variant="body2" color="text.secondary">
@@ -94,7 +94,7 @@ export default function Shortlists() {
                 }}
               >
                 <Box>
-                  <Typography variant="subtitle1" fontWeight={700}>
+                  <Typography variant="subtitle1" sx={{ fontWeight: 700 }}>
                     {sl.title}
                   </Typography>
                   <Typography variant="body2" color="text.secondary">
@@ -135,8 +135,7 @@ export default function Shortlists() {
                       }}
                     />
                     <ListItemText
-                      primary={prop}
-                      primaryTypographyProps={{ variant: 'body2' }}
+                      primary={<Typography variant="body2">{prop}</Typography>}
                     />
                   </ListItem>
                 ))}
@@ -163,7 +162,7 @@ export default function Shortlists() {
               bgcolor: '#fafafa',
             }}
           >
-            <Typography variant="body2" color="text.secondary" textAlign="center">
+            <Typography variant="body2" color="text.secondary" sx={{ textAlign: 'center' }}>
               Objekte aus den Suchergebnissen zur Shortlist hinzufügen
             </Typography>
           </Card>