fix: mock sharp in tests to prevent CI failure on linux

tests/setup.ts

@@ -0,0 +1,10 @@
+import { vi } from "vitest";
+
+// Mock sharp globally — it's a native binary module that may not be available in CI
+vi.mock("sharp", () => ({
+  default: vi.fn().mockReturnValue({
+    png: vi.fn().mockReturnValue({
+      toBuffer: vi.fn().mockResolvedValue(Buffer.from("mock-image")),
+    }),
+  }),
+}));

vite.config.ts

@@ -4,7 +4,6 @@ import { defineConfig } from 'vite'
 
 export default defineConfig({
   test: {
-    /* for example, use global to avoid globals imports (describe, test, expect): */
-    // globals: true,
+    setupFiles: ['./tests/setup.ts'],
   },
 })