feat(remote): support authenticated deletion of remote branches

Add support for authenticated deletion of remote branches and folders.
The backend adds a batch delete command that queries the remote,
performs an atomic push --delete when possible with a fallback, and
prunes stale tracking refs; it accepts optional credentials. The
frontend and JS API integrate credential handling and prompt users when
authentication is required.

- New batch deletion command with optional username/password for auth.
- Uses ls-remote to scope deletions, tries --atomic then falls back.
- Frontend updates: credential dialog/action, pendingRemoteDelete state.

src-tauri/src/main.rs

@@ -16,8 +16,8 @@ use git::{
     commit_ai_load, commit_ai_local_models, commit_ai_review, commit_ai_split, commit_ai_status,
     compare_commits, compare_file_to_head, compare_file_to_parent, create_branch, create_tag,
     cred_delete, cred_load, cred_save, delete_branch, delete_commit_note, delete_remote_branch,
-    delete_tag, diff_file_against_working_tree, fetch, fetch_commit_notes, get_commit_note,
-    get_file_blame, get_file_patch, get_remote_url, get_status, init_repository,
+    delete_remote_branches, delete_tag, diff_file_against_working_tree, fetch, fetch_commit_notes,
+    get_commit_note, get_file_blame, get_file_patch, get_remote_url, get_status, init_repository,
     last_commit_message, list_branches, list_commits, list_file_history,
     list_interactive_rebase_commits, list_reflog, list_remotes, list_repository_files,
     list_stashes, list_tags, list_worktrees, lock_worktree, merge_abort, merge_branch,
@@ -141,6 +141,7 @@ async fn main() {
             remove_remote,
             set_branch_upstream,
             delete_remote_branch,
+            delete_remote_branches,
             list_stashes,
             checkout_branch,
             create_branch,