fix(ui): filter deleted probes from latency chart stats

Stats records in the DB contain historical data for all probes including
deleted ones. Now filters stats by active probe keys and clears state
when all probes are removed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/site/src/components/routes/system/network-probes.tsx

@@ -47,9 +47,16 @@ export default function NetworkProbes({
 		fetchProbes()
 	}, [fetchProbes])
 
+	// Build set of current probe keys to filter out deleted probes from stats
+	const activeProbeKeys = useMemo(() => new Set(probes.map(probeKey)), [probes])
+
 	// Fetch probe stats based on chart time
 	useEffect(() => {
-		if (probes.length === 0) return
+		if (probes.length === 0) {
+			setStats([])
+			setLatestResults({})
+			return
+		}
 		const controller = new AbortController()
 		const statsType = chartTimeData[chartTime]?.type ?? "1m"
 
@@ -58,10 +65,16 @@ export default function NetworkProbes({
 			signal: controller.signal,
 		})
 			.then((raw) => {
-				const data: NetworkProbeStatsRecord[] = raw.map((r) => ({
-					stats: r.stats,
-					created: new Date(r.created).getTime(),
-				}))
+				// Filter stats to only include currently active probes
+				const data: NetworkProbeStatsRecord[] = raw.map((r) => {
+					const filtered: NetworkProbeStatsRecord["stats"] = {}
+					for (const [key, val] of Object.entries(r.stats)) {
+						if (activeProbeKeys.has(key)) {
+							filtered[key] = val
+						}
+					}
+					return { stats: filtered, created: new Date(r.created).getTime() }
+				})
 				setStats(data)
 				if (data.length > 0) {
 					const last = data[data.length - 1].stats
@@ -75,7 +88,7 @@ export default function NetworkProbes({
 			.catch(() => setStats([]))
 
 		return () => controller.abort()
-	}, [systemId, chartTime, probes])
+	}, [systemId, chartTime, probes, activeProbeKeys])
 
 	const deleteProbe = async (id: string) => {
 		try {