fix: add Switch mock to EPG test for SD logo toggle

Frontend test was failing because the Mantine core mock didn't include
the Switch component used by the SD logo style picker.

frontend/src/components/forms/__tests__/EPG.test.jsx

@@ -223,6 +223,18 @@ vi.mock('@mantine/core', async () => ({
   ScrollArea: ({ children }) => <div data-testid="scroll-area">{children}</div>,
   Table: ({ children }) => <table>{children}</table>,
   Tooltip: ({ children }) => <div>{children}</div>,
+  Switch: ({ label, checked, onChange, disabled, description }) => (
+    <label>
+      <input
+        type="checkbox"
+        data-testid={`switch-${label?.toString().toLowerCase().replace(/\s+/g, '-')}`}
+        checked={checked ?? false}
+        onChange={(e) => onChange?.(e)}
+        disabled={disabled}
+      />
+      {label}
+    </label>
+  ),
 }));
 
 // ── Imports after mocks ────────────────────────────────────────────────────────