feat(branches): add bulk delete for branch folders

Add a context-menu action to delete all branches in a folder at once.
Top-level remote folders are protected and the currently checked-out branch
is preserved. The BranchPanel API now includes folder depth to prevent
accidental bulk-deletes and summarizes individual failures after processing.
UI polish and localization were applied, and the package/version metadata,
changelog, and help overlay were updated for the 2026.8.4 release.

- Bulk delete with top-level remote protection and failure summaries.
- BranchPanel now tracks folder depth and disables unsafe context menus.
- Version bump, changelog/help overlay updates, and UI/localization tweaks.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "gitty",
-  "version": "2026.8.3",
+  "version": "2026.8.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "gitty",
-      "version": "2026.8.3",
+      "version": "2026.8.4",
       "dependencies": {
         "@lucide/svelte": "^1.21.0",
         "@tailwindcss/vite": "^4.3.1",