First draft of repeater telemetry feature

frontend/src/test/setup.ts

@@ -7,3 +7,19 @@ class ResizeObserver {
 }
 
 globalThis.ResizeObserver = ResizeObserver;
+
+// uPlot calls matchMedia at import time for DPI detection
+if (typeof globalThis.matchMedia === 'undefined') {
+  Object.defineProperty(globalThis, 'matchMedia', {
+    value: (query: string) => ({
+      matches: false,
+      media: query,
+      onchange: null,
+      addListener: () => {},
+      removeListener: () => {},
+      addEventListener: () => {},
+      removeEventListener: () => {},
+      dispatchEvent: () => false,
+    }),
+  });
+}