fix(beszel): widget transparency, error handling, and cache invalidation

- Remove hardcoded background colors from Beszel grid/table widgets so
  the board's opacity slider controls the background via the parent
  card's --background-color CSS variable
- Grid: set bg="transparent" on inner Card components
- Table: override mantine-datatable default backgrounds to transparent
- Stats: make system selector toggle only visible on hover
- Stats: fix chart width/height(-1) warning by setting minHeight: 1
- All Beszel widgets: throw query errors to trigger the ErrorBoundary
  instead of silently rendering an empty/black UI
- Add retry: false to beszel-system-stats queries
- Add invalidateIntegrationCacheAsync() to clear all cached data and
  session stores for an integration when it is updated or deleted,
  preventing stale/errored data from persisting after config changes

packages/redis/src/index.ts

@@ -15,6 +15,7 @@ export {
   createGetSetChannel,
   createQueryCacheChannel,
   getAllQueryCacheAsync,
+  invalidateIntegrationCacheAsync,
 } from "./lib/channel";
 
 export { createIntegrationHistoryChannel } from "./lib/channels/history-channel";

packages/redis/src/lib/channel.ts

@@ -261,6 +261,31 @@ export const createIntegrationOptionsChannel = <TData>(
   return createChannelWithLatestAndEvents<TData>(channelName);
 };
 
+/**
+ * Invalidates all cached data for a given integration by deleting every Redis key
+ * that starts with `integration:${integrationId}:` as well as the integration's
+ * session store entry. This ensures that stale data from a misconfigured or
+ * updated integration is never served from cache.
+ */
+export const invalidateIntegrationCacheAsync = async (integrationId: string): Promise<void> => {
+  const patterns = [`integration:${integrationId}:*`, `session-store:${integrationId}`];
+  let deletedCount = 0;
+  for (const pattern of patterns) {
+    let cursor = "0";
+    do {
+      const [nextCursor, keys] = await getSetClient.scan(cursor, "MATCH", pattern, "COUNT", 200);
+      cursor = nextCursor;
+      if (keys.length > 0) {
+        await getSetClient.del(...keys);
+        deletedCount += keys.length;
+      }
+    } while (cursor !== "0");
+  }
+  if (deletedCount > 0) {
+    logger.info("Invalidated integration cache", { integrationId, deletedKeys: deletedCount });
+  }
+};
+
 export const createWidgetOptionsChannel = <TData>(
   widgetKind: WidgetKind,
   queryKey: string,