Add poster image support to Matrix download listings

- Fetch and display poster images for tracked items in Matrix
- Show monitored/unmonitored icons in listings
- Limit displayed items to 12, with count and overflow message
- Add tests for image fetching and formatting
- Enable Grafana datasources
- Fix Sonarr/Radarr URL config bug

packages/arrtrix/pkg/arrclient/client_test.go

@@ -0,0 +1,80 @@
+package arrclient
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+)
+
+func TestImageURLPrefersPosterAndResolvesRelativePath(t *testing.T) {
+	baseURL, err := url.Parse("https://radarr.example")
+	if err != nil {
+		t.Fatalf("failed to parse base URL: %v", err)
+	}
+
+	client := &httpClient{baseURL: baseURL}
+	imageURL := client.imageURL([]mediaImage{
+		{CoverType: "fanart", URL: "/MediaCover/1/fanart.jpg"},
+		{CoverType: "poster", URL: "/MediaCover/1/poster.jpg"},
+	})
+	if imageURL != "https://radarr.example/MediaCover/1/poster.jpg" {
+		t.Fatalf("unexpected image URL %q", imageURL)
+	}
+}
+
+func TestImageURLFallsBackToRemoteURL(t *testing.T) {
+	baseURL, err := url.Parse("https://sonarr.example")
+	if err != nil {
+		t.Fatalf("failed to parse base URL: %v", err)
+	}
+
+	client := &httpClient{baseURL: baseURL}
+	imageURL := client.imageURL([]mediaImage{
+		{CoverType: "poster", RemoteURL: "https://images.example/poster.jpg"},
+	})
+	if imageURL != "https://images.example/poster.jpg" {
+		t.Fatalf("unexpected remote image URL %q", imageURL)
+	}
+}
+
+func TestFetchImageUsesAPIKeyForSameHost(t *testing.T) {
+	headers := make(chan string, 1)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		headers <- r.Header.Get("X-Api-Key")
+		w.Header().Set("Content-Type", "image/jpeg")
+		_, _ = w.Write([]byte("jpeg-bytes"))
+	}))
+	defer server.Close()
+
+	client, err := newHTTPClient(server.URL, "secret")
+	if err != nil {
+		t.Fatalf("failed to create client: %v", err)
+	}
+
+	asset, err := client.FetchImage(context.Background(), ManagedItem{
+		ID:       42,
+		Title:    "Dune Part Two",
+		ImageURL: server.URL + "/MediaCover/42/poster.jpg",
+	})
+	if err != nil {
+		t.Fatalf("failed to fetch image: %v", err)
+	}
+	if asset == nil {
+		t.Fatal("expected media asset")
+	}
+	if got := <-headers; got != "secret" {
+		t.Fatalf("expected API key header, got %q", got)
+	}
+	if got := string(asset.Data); got != "jpeg-bytes" {
+		t.Fatalf("unexpected media bytes %q", got)
+	}
+	if asset.MimeType != "image/jpeg" {
+		t.Fatalf("unexpected mime type %q", asset.MimeType)
+	}
+	if !strings.HasPrefix(asset.FileName, "Dune-Part-Two-42") || !strings.HasSuffix(asset.FileName, ".jpg") {
+		t.Fatalf("unexpected filename %q", asset.FileName)
+	}
+}