Show placeholder for empty location in Equipment screen

Display "No location set" in italic style when sensor has no location configured.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/(tabs)/beneficiaries/[id]/equipment.tsx

@@ -451,9 +451,12 @@ export default function EquipmentScreen() {
                           <Text style={styles.deviceMetaSeparator}>•</Text>
                           <Text style={styles.deviceRoom}>{formatLastSeen(sensor.lastSeen)}</Text>
                         </View>
-                        {sensor.location && (
-                          <Text style={styles.deviceLocation}>{sensor.location}</Text>
-                        )}
+                        <Text style={[
+                          styles.deviceLocation,
+                          !sensor.location && styles.deviceLocationPlaceholder
+                        ]}>
+                          {sensor.location || 'No location set'}
+                        </Text>
                       </View>
                     </View>
 
@@ -867,4 +870,8 @@ const styles = StyleSheet.create({
     color: AppColors.textMuted,
     marginTop: 2,
   },
+  deviceLocationPlaceholder: {
+    fontStyle: 'italic',
+    opacity: 0.6,
+  },
 });