Add WebDAV sync provider (manual + auto-sync, top-bar button)

src-tauri/src/lib.rs

@@ -4,6 +4,7 @@ mod commands;
 mod history;
 mod search;
 mod state;
+mod sync;
 mod types;
 mod vault;
 
@@ -159,6 +160,9 @@ pub fn run() {
             commands::set_ai_settings,
             commands::test_ai_connection,
             commands::ai_ask,
+            commands::set_sync_settings,
+            commands::test_sync_connection,
+            commands::sync_now,
             commands::get_install_type,
             commands::get_pending_open_file,
         ])