Camera connection quality indicator (#21297)

* add camera connection quality metrics and indicator

* formatting

* move stall calcs to watchdog

* clean up

* change watchdog to 1s and separately track time for ffmpeg retry_interval

* implement status caching to reduce message volume

web/src/components/camera/ConnectionQualityIndicator.tsx

@@ -0,0 +1,76 @@
+import { useTranslation } from "react-i18next";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+} from "@/components/ui/tooltip";
+import { cn } from "@/lib/utils";
+
+type ConnectionQualityIndicatorProps = {
+  quality: "excellent" | "fair" | "poor" | "unusable";
+  expectedFps: number;
+  reconnects: number;
+  stalls: number;
+};
+
+export function ConnectionQualityIndicator({
+  quality,
+  expectedFps,
+  reconnects,
+  stalls,
+}: ConnectionQualityIndicatorProps) {
+  const { t } = useTranslation(["views/system"]);
+
+  const getColorClass = (quality: string): string => {
+    switch (quality) {
+      case "excellent":
+        return "bg-success";
+      case "fair":
+        return "bg-yellow-500";
+      case "poor":
+        return "bg-orange-500";
+      case "unusable":
+        return "bg-destructive";
+      default:
+        return "bg-gray-500";
+    }
+  };
+
+  const qualityLabel = t(`cameras.connectionQuality.${quality}`);
+
+  return (
+    <Tooltip>
+      <TooltipTrigger asChild>
+        <div
+          className={cn(
+            "inline-block size-3 cursor-pointer rounded-full",
+            getColorClass(quality),
+          )}
+        />
+      </TooltipTrigger>
+      <TooltipContent className="max-w-xs">
+        <div className="space-y-2">
+          <div className="font-semibold">
+            {t("cameras.connectionQuality.title")}
+          </div>
+          <div className="text-sm">
+            <div className="capitalize">{qualityLabel}</div>
+            <div className="mt-2 space-y-1 text-xs">
+              <div>
+                {t("cameras.connectionQuality.expectedFps")}:{" "}
+                {expectedFps.toFixed(1)} {t("cameras.connectionQuality.fps")}
+              </div>
+              <div>
+                {t("cameras.connectionQuality.reconnectsLastHour")}:{" "}
+                {reconnects}
+              </div>
+              <div>
+                {t("cameras.connectionQuality.stallsLastHour")}: {stalls}
+              </div>
+            </div>
+          </div>
+        </div>
+      </TooltipContent>
+    </Tooltip>
+  );
+}