feat: identity protection UI, duplicate guards, name-lock enforcement (v2.4.6)

- Add password set/change/remove with loading states and double-click prevention
- Add protected identity deletion flow (server-side password removal first)
- Add restore flow for password-protected UUIDs (verify password before saving)
- Add UUID duplicate checks in setUuidForUser (prevent accidental overwrites)
- Add name-locked error handling in launch flow (server enforces registered name)
- Sync shield icon across all identity mutation paths
- Refresh identity dropdown after all password/identity operations
- Propagate force flag through IPC for legitimate overwrites

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hytale-f2p-launcher",
-  "version": "2.4.5",
+  "version": "2.4.6",
   "description": "A modern, cross-platform launcher for Hytale with automatic updates and multi-client support",
   "homepage": "https://git.sanhost.net/sanasol/hytale-f2p",
   "main": "main.js",