Add Reset all data to Settings > Data and release 1.2.0

Reset all data stages a wipe behind a typed RESET confirmation and applies it
on the next start, before the database is opened. It deletes the database,
assets, PDF archive, imported fonts and every backup, then the setup wizard
shows again.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/lib/api.ts

@@ -122,6 +122,8 @@ export const api = {
   getBackupStatus: () => invoke<BackupStatus>("get_backup_status"),
   setAutoBackup: (enabled: boolean) => invoke<boolean>("set_auto_backup", { enabled }),
   restartApp: () => invoke<void>("restart_app"),
+  // Stages a wipe of all data; it is carried out by the next start (see commands/reset.rs), so restart afterwards.
+  resetAllData: () => invoke<void>("reset_all_data"),
 
   // ERPNext integration. All HTTP runs in Rust; the API secret is write-only from the webview.
   erpnextGetConfig: () => invoke<ErpnextConfig>("erpnext_get_config"),