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.

PKGBUILD-bin

@@ -1,7 +1,7 @@
 # Maintainer: Christoph Brandau <c.brandau91@googlemail.com>
 
 pkgname=gitty-desktop-bin
-pkgver=2026.8.3
+pkgver=2026.8.4
 pkgrel=1
 pkgdesc="A lightweight, modern Git client built with Tauri (prebuilt AppImage)"
 arch=('x86_64')
@@ -14,7 +14,7 @@ options=('!strip')
 
 _appimage="Gitty_${pkgver}_amd64.AppImage"
 _artifact_url="https://cdn.cbsk-tech.de/gitty/${pkgver}/${_appimage}"
-_tag=2026.8.3
+_tag=2026.8.4
 source=("${_appimage}::${_artifact_url}"
         "gitty-desktop.png::${url}/raw/tag/${_tag}/src-tauri/icons/icon.png")
 sha256sums=('SKIP'