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/account/ui/AccountPage.module.css

@@ -124,3 +124,24 @@
 	padding-left: 0;
 	padding-right: 0;
 }
+
+.accountPositions {
+	list-style: none;
+	padding: 0;
+	margin: var(--mantine-spacing-sm) 0 0;
+}
+
+.accountPosition {
+	padding-block: var(--mantine-spacing-sm);
+	border-top: 1px solid var(--mantine-color-gray-3);
+	overflow-wrap: anywhere;
+}
+
+.accountPosition:last-child {
+	padding-bottom: 0;
+}
+
+.accountPositionName {
+	min-width: 0;
+	overflow-wrap: anywhere;
+}