feat: show persisted investment data and sync state

Consume the provided resource-envelope API snapshot. Preserve financial snapshots during
refresh, observe synchronization without importing, and fence late responses across
account and connection changes.

src/entities/brokerage-event/ui/BrokerageEventsPreview/BrokerageEventsPreview.tsx

@@ -3,6 +3,7 @@ import { LoadingSkeleton } from "@wealthledger/ui";
 import type { FC } from "react";
 import { useTranslation } from "react-i18next";
 import { Link } from "react-router";
+import { formatSnapshotTime } from "@/shared/lib";
 import type { BrokerageEvent } from "../../api/useBrokerageEvents";
 import { BrokerageEventCard } from "../BrokerageEventCard";
 
@@ -12,7 +13,14 @@ type BrokerageEventsPreviewProps = {
 
 type BrokerageEventsPreviewState =
 	| { state: "loading" | "error" | "empty"; to: string }
-	| { state: "loaded"; to: string; items: BrokerageEvent[] };
+	| {
+			state: "loaded" | "partial";
+			to: string;
+			lastSuccessfulAt?: string | null;
+			stale?: boolean;
+			refreshError?: boolean;
+			items: BrokerageEvent[];
+	  };
 
 const BrokerageEventsPreview: FC<BrokerageEventsPreviewProps> = (props) => {
 	const { events } = props;
@@ -20,6 +28,21 @@ const BrokerageEventsPreview: FC<BrokerageEventsPreviewProps> = (props) => {
 
 	return (
 		<Stack gap="sm">
+			{events.state === "loaded" ? (
+				<>
+					{events.lastSuccessfulAt ? (
+						<Text size="xs" c="dimmed">
+							{t("investment.sourceTime", {
+								date: formatSnapshotTime(events.lastSuccessfulAt),
+							})}
+						</Text>
+					) : null}
+					{events.stale ? <Text size="xs">{t("investment.stale")}</Text> : null}
+					{events.refreshError ? (
+						<Text role="status">{t("accounts.refreshError")}</Text>
+					) : null}
+				</>
+			) : null}
 			{events.state === "loading" ? (
 				<LoadingSkeleton label={t("events.recentLoading")}>
 					{[0, 1, 2].map((index) => (
@@ -33,7 +56,10 @@ const BrokerageEventsPreview: FC<BrokerageEventsPreviewProps> = (props) => {
 			{events.state === "empty" ? (
 				<Text c="dimmed">{t("events.recentEmpty")}</Text>
 			) : null}
-			{events.state === "loaded"
+			{events.state === "partial" ? (
+				<Text role="status">{t("investment.partial")}</Text>
+			) : null}
+			{events.state === "loaded" || events.state === "partial"
 				? events.items.map((event) => (
 						<BrokerageEventCard
 							key={JSON.stringify([