feat: P2.3 Folder Sharing + P2.5 Email Import + P2.6 Contact Import + P2.7 Free/Busy

- P2.3: Folder sharing system — ShareFolderDialog, sharing-store, sharing-settings
- P2.5: Email import (.eml, .tgz, .zip) with dedup and progress
- P2.6: Contact import (vCard + CSV) with auto-mapping
- P2.7: Free/Busy view grid with color-coded slots

components/settings/contacts-settings.tsx

@@ -18,6 +18,7 @@ export function ContactsSettings() {
   const { client } = useAuthStore();
   const {
     contacts,
+    addressBooks,
     supportsSync,
     importContacts,
   } = useContactStore();
@@ -46,6 +47,7 @@ export function ContactsSettings() {
       <div className="border border-border rounded-lg overflow-hidden" style={{ minHeight: 400 }}>
         <ContactImportDialog
           existingContacts={contacts}
+          addressBooks={addressBooks}
           onImport={handleImport}
           onClose={() => setShowImport(false)}
         />