spec(grafana-metric-gateway): verify + close GM-115 + reconcile tracking

Add 3 test cases (startup old-config validation warning; status auth_failed
for 401/403) closing the GM-115 PARTIAL. Write apply-progress.md, tick all 33
tasks, add verify-report.md (15/16 PASS, 1 PARTIAL->PASS). Gates green: 331+
pytest, ruff clean, npm build+lint 0 errors, 151 vitest.

frontend/src/widgets/PrometheusMetricWidget.tsx

@@ -50,7 +50,7 @@ export function PrometheusMetricWidget({
 				<Alert variant="destructive">
 					<AlertDescription>{data.error}</AlertDescription>
 				</Alert>
-		) : (
+			) : (
 				<pre className="whitespace-pre-wrap text-sm">
 					{formatMetricResult(series)}
 				</pre>