feat: show contacts from all logged-in accounts in Pro shell

hooks/use-pro-multi-account-contacts.ts

@@ -0,0 +1,48 @@
+"use client";
+
+import { useEffect, useMemo } from "react";
+import { useAccountStore } from "@/stores/account-store";
+import { useAuthStore } from "@/stores/auth-store";
+import { useContactStore, type ContactAccountClient } from "@/stores/contact-store";
+import { useSettingsStore } from "@/stores/settings-store";
+import { useIsEmbedded } from "@/hooks/use-is-embedded";
+
+/**
+ * Pro-shell counterpart to [[useProMultiAccountCalendars]] — aggregates
+ * contacts and address books from every connected JMAP account so the
+ * contacts sidebar lists them all, grouped by local account.
+ */
+export function useProMultiAccountContacts(): {
+  enabled: boolean;
+  accountClients: ContactAccountClient[];
+} {
+  const isEmbedded = useIsEmbedded();
+  const proInterface = useSettingsStore((s) => s.proInterface);
+  const accounts = useAccountStore((s) => s.accounts);
+  const activeAccountId = useAuthStore((s) => s.activeAccountId);
+  const fetchAllAccountsAddressBooks = useContactStore((s) => s.fetchAllAccountsAddressBooks);
+  const fetchAllAccountsContacts = useContactStore((s) => s.fetchAllAccountsContacts);
+
+  const enabled = proInterface || isEmbedded;
+
+  const accountClients = useMemo(() => {
+    if (!enabled) return [];
+    const getClientForAccount = useAuthStore.getState().getClientForAccount;
+    const pairs: ContactAccountClient[] = [];
+    for (const account of accounts) {
+      if (!account.isConnected) continue;
+      const client = getClientForAccount(account.id);
+      if (!client || !client.supportsContacts()) continue;
+      pairs.push({ localAccountId: account.id, client });
+    }
+    return pairs;
+  }, [enabled, accounts]);
+
+  useEffect(() => {
+    if (!enabled || !activeAccountId || accountClients.length === 0) return;
+    void fetchAllAccountsAddressBooks(accountClients, activeAccountId);
+    void fetchAllAccountsContacts(accountClients, activeAccountId);
+  }, [enabled, activeAccountId, accountClients, fetchAllAccountsAddressBooks, fetchAllAccountsContacts]);
+
+  return { enabled, accountClients };
+}