Add tappable cards, detail bottom sheet, swipe gestures, and favorites view

- Decision types, services (decisionService, listingDetailService), and index exports
- useDecisions hook with optimistic updates and Map-based state
- useListingDetail hook with session-level caching
- PhotoCarousel component using embla-carousel-react
- ListingDetail component with full property info, like/dislike buttons
- ListingDetailSheet using vaul Drawer (slide-up bottom sheet)
- SwipeablePropertyCard with @use-gesture/react and @react-spring/web
- SwipeReviewMode for mobile full-screen swipe review
- FavoritesView with virtualized liked listings and remove button
- App.tsx integration: decision state, client-side disliked filtering, detail sheet, swipe handlers
- ListView conditionally renders SwipeablePropertyCard when handlers provided
- StatsBar adds 'saved' view mode with heart icon
- Header adds liked count indicator
- New deps: vaul, embla-carousel-react, @use-gesture/react, @react-spring/web

frontend/package-lock.json

@@ -39,6 +39,7 @@
         "crossfilter2": "^1.5.4",
         "d3": "^7.9.0",
         "date-fns": "^4.1.0",
+        "embla-carousel-react": "^8.6.0",
         "lucide-react": "^0.515.0",
         "mapbox-gl": "^3.12.0",
         "oidc-client-ts": "^3.2.1",
@@ -5088,6 +5089,34 @@
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       "license": "ISC"
     },
+    "node_modules/embla-carousel": {
+      "version": "8.6.0",
+      "resolved": "https://registry.npmjs.org/embla-carousel/-/embla-carousel-8.6.0.tgz",
+      "integrity": "sha512-SjWyZBHJPbqxHOzckOfo8lHisEaJWmwd23XppYFYVh10bU66/Pn5tkVkbkCMZVdbUE5eTCI2nD8OyIP4Z+uwkA==",
+      "license": "MIT"
+    },
+    "node_modules/embla-carousel-react": {
+      "version": "8.6.0",
+      "resolved": "https://registry.npmjs.org/embla-carousel-react/-/embla-carousel-react-8.6.0.tgz",
+      "integrity": "sha512-0/PjqU7geVmo6F734pmPqpyHqiM99olvyecY7zdweCw+6tKEXnrE90pBiBbMMU8s5tICemzpQ3hi5EpxzGW+JA==",
+      "license": "MIT",
+      "dependencies": {
+        "embla-carousel": "8.6.0",
+        "embla-carousel-reactive-utils": "8.6.0"
+      },
+      "peerDependencies": {
+        "react": "^16.8.0 || ^17.0.1 || ^18.0.0 || ^19.0.0 || ^19.0.0-rc"
+      }
+    },
+    "node_modules/embla-carousel-reactive-utils": {
+      "version": "8.6.0",
+      "resolved": "https://registry.npmjs.org/embla-carousel-reactive-utils/-/embla-carousel-reactive-utils-8.6.0.tgz",
+      "integrity": "sha512-fMVUDUEx0/uIEDM0Mz3dHznDhfX+znCCDCeIophYb1QGVM7YThSWX+wz11zlYwWFOr74b4QLGg0hrGPJeG2s4A==",
+      "license": "MIT",
+      "peerDependencies": {
+        "embla-carousel": "8.6.0"
+      }
+    },
     "node_modules/emoji-regex": {
       "version": "8.0.0",
       "resolved": "https://registry.npmjs.org/emoji-regex/-/emoji-regex-8.0.0.tgz",