perf: add promise deduplication for getAssetInfo (#134)

Add Promise deduplication (request coalescing) to the `getAssetInfo`
method in `ImmichClient` (`lib/immich.ts`) to prevent concurrent
identical requests from firing multiple times to the Immich server.
This is particularly helpful when calling `Promise.all` on multiple
assets concurrently (e.g. hero images on the homepage or multiple
album cover placeholder hashes).

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

lib/immich.ts

@@ -74,6 +74,7 @@ class ImmichClient {
   private hasLoggedAlbums = false;
   private pendingAlbumsPromise: Promise<ImmichAlbum[]> | null = null;
   private pendingAlbumPromises = new Map<string, Promise<ImmichAlbum | null>>();
+  private pendingAssetPromises = new Map<string, Promise<ImmichAsset | null>>();
 
   private get config() {
     return getConfig();
@@ -344,11 +345,27 @@ class ImmichClient {
     const cached = cache.get<ImmichAsset>(cacheKey);
     if (cached) return cached;
 
-    const asset = await this.request<ImmichAsset>(`/assets/${encodeURIComponent(assetId)}`);
-    if (!asset) return null;
+    // ⚡ Bolt: Deduplicate concurrent requests for the same asset ID.
+    // If a request for this asset is already in flight (e.g. from Promise.all in a grid),
+    // return the pending promise instead of triggering a redundant API call.
+    if (this.pendingAssetPromises.has(assetId)) {
+      return this.pendingAssetPromises.get(assetId)!;
+    }
 
-    cache.set(cacheKey, asset, this.config.cacheTtl);
-    return asset;
+    const promise = (async () => {
+      try {
+        const asset = await this.request<ImmichAsset>(`/assets/${encodeURIComponent(assetId)}`);
+        if (!asset) return null;
+
+        cache.set(cacheKey, asset, this.config.cacheTtl);
+        return asset;
+      } finally {
+        this.pendingAssetPromises.delete(assetId);
+      }
+    })();
+
+    this.pendingAssetPromises.set(assetId, promise);
+    return promise;
   }
 
   /**