Add StandingsPreview component tests covering avatar rendering

Tests were missing for the StandingsPreview component, which is the
component that actually renders team avatars on the full standings page.
Covers uploaded image, flag SVG, owner avatar inheritance, and the
generated-flag fallback, plus basic content rendering (team names,
owner names, points, description, full standings link).

https://claude.ai/code/session_01CVt5Vo2PDGY4G3wSWbsmRG

app/components/league/__tests__/StandingsPreview.test.tsx

@@ -0,0 +1,104 @@
+import { describe, it, expect } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { BrowserRouter } from "react-router";
+import { StandingsPreview, type StandingsPreviewEntry } from "../StandingsPreview";
+
+function renderWithRouter(ui: React.ReactElement) {
+  return render(<BrowserRouter>{ui}</BrowserRouter>);
+}
+
+const baseEntry: StandingsPreviewEntry = {
+  teamId: "team-1",
+  teamName: "Lightning Wolves",
+  ownerName: "alice",
+  displayRank: 1,
+  currentRank: 1,
+  points: 2500,
+  href: "/leagues/1/standings/1/teams/team-1",
+};
+
+describe("StandingsPreview", () => {
+  describe("Avatar rendering", () => {
+    it("renders an img for uploaded avatar type", () => {
+      const entry: StandingsPreviewEntry = {
+        ...baseEntry,
+        avatarType: "uploaded",
+        logoUrl: "https://example.com/team-logo.png",
+      };
+      renderWithRouter(<StandingsPreview entries={[entry]} />);
+
+      const img = screen.getByAltText("Lightning Wolves");
+      expect(img.tagName).toBe("IMG");
+    });
+
+    it("renders an SVG for flag avatar type", () => {
+      const entry: StandingsPreviewEntry = {
+        ...baseEntry,
+        avatarType: "flag",
+        flagConfig: { pattern: "triband-h", colors: ["#ff0000", "#ffffff", "#0000ff"] },
+      };
+      const { container } = renderWithRouter(<StandingsPreview entries={[entry]} />);
+
+      expect(container.querySelector("svg")).toBeInTheDocument();
+    });
+
+    it("renders owner image when avatarType is owner with image ownerAvatarData", () => {
+      const entry: StandingsPreviewEntry = {
+        ...baseEntry,
+        avatarType: "owner",
+        ownerAvatarData: { type: "image", url: "https://example.com/owner.png" },
+      };
+      renderWithRouter(<StandingsPreview entries={[entry]} />);
+
+      const img = screen.getByAltText("Lightning Wolves");
+      expect(img.tagName).toBe("IMG");
+    });
+
+    it("falls back to a generated flag when no avatar data is provided", () => {
+      const entry: StandingsPreviewEntry = { ...baseEntry, avatarType: undefined };
+      const { container } = renderWithRouter(<StandingsPreview entries={[entry]} />);
+
+      expect(container.querySelector("svg")).toBeInTheDocument();
+    });
+  });
+
+  describe("Basic rendering", () => {
+    it("renders team names for all entries", () => {
+      const entries: StandingsPreviewEntry[] = [
+        { ...baseEntry, teamId: "t1", teamName: "Team Alpha", displayRank: 1 },
+        { ...baseEntry, teamId: "t2", teamName: "Team Beta", displayRank: 2 },
+      ];
+      renderWithRouter(<StandingsPreview entries={entries} />);
+
+      expect(screen.getByText("Team Alpha")).toBeInTheDocument();
+      expect(screen.getByText("Team Beta")).toBeInTheDocument();
+    });
+
+    it("renders owner name below team name", () => {
+      renderWithRouter(<StandingsPreview entries={[baseEntry]} />);
+
+      expect(screen.getByText("alice")).toBeInTheDocument();
+    });
+
+    it("renders rounded points", () => {
+      renderWithRouter(<StandingsPreview entries={[{ ...baseEntry, points: 1500 }]} />);
+
+      expect(screen.getByText("1,500")).toBeInTheDocument();
+    });
+
+    it("renders description when provided", () => {
+      renderWithRouter(<StandingsPreview entries={[baseEntry]} description="Current Standings" />);
+
+      expect(screen.getByText("Current Standings")).toBeInTheDocument();
+    });
+
+    it("renders full standings link when fullStandingsHref is provided", () => {
+      renderWithRouter(
+        <StandingsPreview entries={[baseEntry]} fullStandingsHref="/leagues/1/standings/1" />
+      );
+
+      const link = screen.getByRole("link", { name: "Full Standings" });
+      expect(link).toHaveAttribute("href", "/leagues/1/standings/1");
+    });
+  });
+});