Webdav (#923)

* feat: WebDAV backup/restore

- Add WebDAV test/backup/restore commands and settings\n- Fix ja i18n missing keys; decode PROPFIND href as UTF-8\n- Stabilize Windows prompt auto-import tests via CC_SWITCH_TEST_HOME

* chore: format and minor cleanups

* fix: update build config

* feat(webdav): unify sync UX and hardening fixes

* fix(webdav): harden sync flow and stabilize sync UX/tests

* fix(webdav): add resource limits to skills.zip extraction

Prevent zip bomb / resource exhaustion by enforcing:
- MAX_EXTRACT_ENTRIES (10,000 files)
- MAX_EXTRACT_BYTES (512 MB cumulative)

* refactor(webdav): drop deviceId and display deviceName only

---------

Co-authored-by: small-lovely-cat <77799160+small-lovely-cat@users.noreply.github.com>
Co-authored-by: saladday <1203511142@qq.com>

src/lib/api/settings.ts

@@ -1,5 +1,5 @@
 import { invoke } from "@tauri-apps/api/core";
-import type { Settings } from "@/types";
+import type { Settings, WebDavSyncSettings, RemoteSnapshotInfo } from "@/types";
 import type { AppId } from "./types";
 
 export interface ConfigTransferResult {
@@ -9,6 +9,15 @@ export interface ConfigTransferResult {
   backupId?: string;
 }
 
+export interface WebDavTestResult {
+  success: boolean;
+  message?: string;
+}
+
+export interface WebDavSyncResult {
+  status: string;
+}
+
 export const settingsApi = {
   async get(): Promise<Settings> {
     return await invoke("get_settings");
@@ -93,6 +102,42 @@ export const settingsApi = {
     return await invoke("import_config_from_file", { filePath });
   },
 
+  // ─── WebDAV v2 sync ───────────────────────────────────────
+
+  async webdavTestConnection(
+    settings: WebDavSyncSettings,
+    preserveEmptyPassword = true,
+  ): Promise<WebDavTestResult> {
+    return await invoke("webdav_test_connection", {
+      settings,
+      preserveEmptyPassword,
+    });
+  },
+
+  async webdavSyncUpload(): Promise<WebDavSyncResult> {
+    return await invoke("webdav_sync_upload");
+  },
+
+  async webdavSyncDownload(): Promise<WebDavSyncResult> {
+    return await invoke("webdav_sync_download");
+  },
+
+  async webdavSyncSaveSettings(
+    settings: WebDavSyncSettings,
+    passwordTouched = false,
+  ): Promise<{ success: boolean }> {
+    return await invoke("webdav_sync_save_settings", {
+      settings,
+      passwordTouched,
+    });
+  },
+
+  async webdavSyncFetchRemoteInfo(): Promise<
+    RemoteSnapshotInfo | { empty: true }
+  > {
+    return await invoke("webdav_sync_fetch_remote_info");
+  },
+
   async syncCurrentProvidersLive(): Promise<void> {
     const result = (await invoke("sync_current_providers_live")) as {
       success?: boolean;