feat: add address book, fix email layout, update dependencies

- Address book with JMAP sync and local fallback (contacts CRUD,
  search/filter, composer autocomplete, i18n for 8 languages)
- Fix email layout: remove horizontal scroll, left-side clipping,
  and empty spaces from blocked external images in newsletters
- Update all dependencies to latest compatible versions
- Expand i18n from 3 to 8 languages (added ES, IT, DE, NL, PT)
- Upgrade Next.js to 16.1.6 for security patches

components/contacts/contact-list-item.tsx

@@ -0,0 +1,44 @@
+"use client";
+
+import { Avatar } from "@/components/ui/avatar";
+import { cn } from "@/lib/utils";
+import type { ContactCard } from "@/lib/jmap/types";
+import { getContactDisplayName, getContactPrimaryEmail } from "@/stores/contact-store";
+
+interface ContactListItemProps {
+  contact: ContactCard;
+  isSelected: boolean;
+  onClick: () => void;
+}
+
+export function ContactListItem({ contact, isSelected, onClick }: ContactListItemProps) {
+  const name = getContactDisplayName(contact);
+  const email = getContactPrimaryEmail(contact);
+  const org = contact.organizations
+    ? Object.values(contact.organizations)[0]?.name
+    : undefined;
+
+  return (
+    <button
+      onClick={onClick}
+      className={cn(
+        "w-full flex items-center gap-3 px-4 py-3 text-left transition-colors",
+        "hover:bg-muted",
+        isSelected && "bg-accent text-accent-foreground"
+      )}
+    >
+      <Avatar name={name} email={email} size="sm" />
+      <div className="flex-1 min-w-0">
+        <div className="text-sm font-medium truncate">
+          {name || email || "—"}
+        </div>
+        {email && name && (
+          <div className="text-xs text-muted-foreground truncate">{email}</div>
+        )}
+        {org && (
+          <div className="text-xs text-muted-foreground truncate">{org}</div>
+        )}
+      </div>
+    </button>
+  );
+}