feat: add all-accounts portfolio pages

Reuse account sections and group securities with per-account holdings.

Use Mantine Select to preserve filters and reset pagination on scope changes.

Document component reuse guardrails and cover routes, grouping and scope switching.

src/pages/accounts/ui/components/AccountsPageLoaded.view.tsx

@@ -1,6 +1,7 @@
-import { Stack, Title } from "@mantine/core";
+import { Button, Stack, Title } from "@mantine/core";
 import type { FC } from "react";
 import { useTranslation } from "react-i18next";
+import { Link } from "react-router";
 import {
 	type BrokerageAccountCard,
 	BrokerageAccountList,
@@ -21,6 +22,14 @@ const AccountsPageLoaded: FC<AccountsPageLoadedProps> = (props) => {
 		<Stack>
 			<Title order={1}>{t("accounts.title")}</Title>
 			<AccountsRefreshState {...refresh} />
+			<Button
+				component={Link}
+				to="/accounts/all"
+				variant="light"
+				w="fit-content"
+			>
+				{t("accounts.openAll")}
+			</Button>
 			<BrokerageAccountList accounts={accounts} />
 		</Stack>
 	);