Refine semantic search and CPU fallback

- make Candle CUDA support opt-in so default builds work on CPU-only machines
- improve semantic search loading and empty states in the gallery
- keep semantic search UX clearer when no matches are found

Refs: #4

src-tauri/Cargo.toml

@@ -12,6 +12,10 @@ crate-type = ["staticlib", "cdylib", "rlib"]
 [build-dependencies]
 tauri-build = { version = "2", features = [] }
 
+[features]
+default = []
+candle-cuda = ["candle-core/cuda", "candle-nn/cuda", "candle-transformers/cuda"]
+
 [dependencies]
 tauri = { version = "2", features = ["protocol-asset"] }
 tauri-plugin-opener = "2"
@@ -35,8 +39,8 @@ log = "0.4"
 ffmpeg-sidecar = "2.5.0"
 xxhash-rust = { version = "0.8", features = ["xxh3"] }
 sysinfo = "0.38.4"
-candle-core = { version = "0.10.2", features = ["cuda"] }
-candle-nn = { version = "0.10.2", features = ["cuda"] }
-candle-transformers = { version = "0.10.2", features = ["cuda"] }
+candle-core = "0.10.2"
+candle-nn = "0.10.2"
+candle-transformers = "0.10.2"
 hf-hub = { version = "0.5.0", default-features = false, features = ["ureq", "native-tls"] }
 tokenizers = "0.22.1"

src-tauri/src/embedder.rs

@@ -84,20 +84,17 @@ impl ClipImageEmbedder {
 }
 
 fn resolve_device() -> Result<Device> {
+    #[cfg(feature = "candle-cuda")]
+    {
         let cuda_device = Device::cuda_if_available(0)?;
         if cuda_device.is_cuda() {
             println!("CLIP embedder using CUDA device.");
             return Ok(cuda_device);
         }
+    }
 
-    #[cfg(target_os = "macos")]
-    {
-        let metal_device = Device::metal_if_available(0)?;
-        if metal_device.is_metal() {
-            println!("CLIP embedder using Metal device.");
-            return Ok(metal_device);
-        }
-    }
+    #[cfg(not(feature = "candle-cuda"))]
+    println!("CLIP embedder built without CUDA support.");
 
     println!("CLIP embedder using CPU device.");
     Ok(Device::Cpu)

src/components/Gallery.tsx

@@ -234,6 +234,8 @@ export function Gallery() {
   const totalImages = useGalleryStore((state) => state.totalImages);
   const loadingImages = useGalleryStore((state) => state.loadingImages);
   const zoomPreset = useGalleryStore((state) => state.zoomPreset);
+  const search = useGalleryStore((state) => state.search);
+  const searchMode = useGalleryStore((state) => state.searchMode);
 
   const parentRef = useRef<HTMLDivElement>(null);
   const [contextMenu, setContextMenu] = useState<{ x: number; y: number; image: ImageRecord } | null>(null);
@@ -270,6 +272,26 @@ export function Gallery() {
     };
   }, []);
 
+  if (images.length === 0 && loadingImages) {
+    return (
+      <div className="flex flex-1 flex-col items-center justify-center gap-4 text-center px-8">
+        <div className="rounded-2xl border border-white/[0.06] bg-white/[0.02] p-8 min-w-72">
+          <div className="h-5 w-5 mx-auto rounded-full border-2 border-white/20 border-t-white/60 animate-spin" />
+          <p className="mt-4 text-sm text-white/40 font-medium">
+            {searchMode === "semantic" && search.trim().length > 0
+              ? `Searching for matches to "${search}"`
+              : "Loading media"}
+          </p>
+          <p className="text-xs text-white/20 mt-1">
+            {searchMode === "semantic" && search.trim().length > 0
+              ? "Semantic search can take a little longer than filename search"
+              : "Fetching results"}
+          </p>
+        </div>
+      </div>
+    );
+  }
+
   if (images.length === 0 && !loadingImages) {
     return (
       <div className="flex flex-1 flex-col items-center justify-center gap-4 text-center px-8">
@@ -278,8 +300,16 @@ export function Gallery() {
             <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={0.75}
               d="M4 16l4.586-4.586a2 2 0 012.828 0L16 16m-2-2l1.586-1.586a2 2 0 012.828 0L20 14m-6-6h.01M6 20h12a2 2 0 002-2V6a2 2 0 00-2-2H6a2 2 0 00-2 2v12a2 2 0 002 2z" />
           </svg>
-          <p className="text-sm text-white/30 font-medium">No media found</p>
-          <p className="text-xs text-white/15 mt-1">Try adjusting your filters or add a new folder</p>
+          <p className="text-sm text-white/30 font-medium">
+            {searchMode === "semantic" && search.trim().length > 0
+              ? "No semantic matches found"
+              : "No media found"}
+          </p>
+          <p className="text-xs text-white/15 mt-1">
+            {searchMode === "semantic" && search.trim().length > 0
+              ? "Try a broader phrase, or wait for more embeddings to finish processing"
+              : "Try adjusting your filters or add a new folder"}
+          </p>
         </div>
       </div>
     );