Reduce frontend polling load and clean stale UI hooks

GameList.Tests/SuggestionTests.cs

@@ -348,6 +348,45 @@ public class SuggestionTests
         Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
     }
 
+    [Fact]
+    public async Task Update_does_not_revalidate_unchanged_screenshot_url()
+    {
+        await using var factory = new TestWebApplicationFactory();
+        var client = factory.CreateClientWithCookies();
+        await client.RegisterAsync("reval");
+
+        var create = await client.PostAsJsonAsync("/api/suggestions", new
+        {
+            Name = "Reachable once",
+            Genre = (string?)null,
+            Description = (string?)null,
+            ScreenshotUrl = "http://example.com/shot.png",
+            YoutubeUrl = (string?)null,
+            GameUrl = (string?)null,
+            MinPlayers = (int?)null,
+            MaxPlayers = (int?)null
+        });
+        create.EnsureSuccessStatusCode();
+        var createdPayload = await create.Content.ReadFromJsonAsync<JsonElement>();
+        var suggestionId = createdPayload.GetProperty("id").GetInt32();
+
+        factory.HttpHandler.SetResponder(_ => new HttpResponseMessage(HttpStatusCode.BadRequest));
+
+        var update = await client.PutAsJsonAsync($"/api/suggestions/{suggestionId}", new
+        {
+            Name = "Reachable once",
+            Genre = "Updated",
+            Description = (string?)null,
+            ScreenshotUrl = "http://example.com/shot.png",
+            YoutubeUrl = (string?)null,
+            GameUrl = (string?)null,
+            MinPlayers = (int?)null,
+            MaxPlayers = (int?)null
+        });
+
+        update.EnsureSuccessStatusCode();
+    }
+
     [Fact]
     public async Task Get_all_requires_vote_phase()
     {