Improve frontend UI/UX: accessibility, discoverability, and cleanup

- Add prefers-reduced-motion support (global CSS + SwipeCard spring config)
- Add dismissible map click hint overlay with localStorage persistence
- Replace generic image alt text with descriptive property info across 4 components
- Rename filter buttons to clarify intent (Show Matching Listings / Scrape New from Rightmove)
- Fix mobile FAB overlap with bottom sheet via dynamic snap-aware positioning
- Add swipe review onboarding overlay with gesture explanations and button labels
- Delete unused components: AppSidebar, ActiveQuery, SavedView

frontend/src/components/PropertyCard.tsx

@@ -86,7 +86,7 @@ function AllPOIDistances({ pois, distances }: { pois: POI[]; distances?: POIDist
     );
 }
 
-function CardCarousel({ photos }: { photos: string[] }) {
+function CardCarousel({ photos, altText }: { photos: string[]; altText?: string }) {
     const [emblaRef, emblaApi] = useEmblaCarousel({ loop: true });
     const [selectedIndex, setSelectedIndex] = useState(0);
 
@@ -105,7 +105,7 @@ function CardCarousel({ photos }: { photos: string[] }) {
         return (
             <img
                 src={photos[0]}
-                alt="Property"
+                alt={altText || "Property"}
                 className="w-full h-full object-cover"
                 loading="lazy"
             />
@@ -120,7 +120,7 @@ function CardCarousel({ photos }: { photos: string[] }) {
                         <div key={i} className="flex-[0_0_100%] min-w-0 h-full">
                             <img
                                 src={url}
-                                alt={`Photo ${i + 1}`}
+                                alt={`Property photo ${i + 1}`}
                                 className="w-full h-full object-cover"
                                 loading="lazy"
                             />
@@ -187,7 +187,10 @@ export function PropertyCard({
                 {/* Photo carousel */}
                 <div className="w-24 h-24 rounded-md overflow-hidden flex-shrink-0 bg-muted">
                     {(property.photos?.length || property.photo_thumbnail) ? (
-                        <CardCarousel photos={property.photos?.length ? property.photos : [property.photo_thumbnail]} />
+                        <CardCarousel
+                            photos={property.photos?.length ? property.photos : [property.photo_thumbnail]}
+                            altText={`${property.rooms}-bed, ${property.qm}m², £${property.total_price.toLocaleString()}`}
+                        />
                     ) : null}
                 </div>
 
@@ -248,7 +251,7 @@ export function PropertyCard({
                     {property.photo_thumbnail && (
                         <img
                             src={property.photo_thumbnail}
-                            alt="Property"
+                            alt={`${property.rooms}-bed, ${property.qm}m², £${property.total_price.toLocaleString()}`}
                             className="w-full h-full object-cover"
                         />
                     )}