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-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "Voiced",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "identifier": "com.bongbetic.voiced",
   "build": {
     "beforeDevCommand": "npm run dev",