Implement repository management view and multi-repo tabs

Introduces a new "Repository Management" view for browsing open and recent repositories. Adds a tabbed interface for quickly switching between multiple active repositories, with persistent state. Also includes a new command to open the current repository in the native file explorer.

src/lib/git.ts

@@ -17,6 +17,10 @@ export function openRepository(path: string): Promise<GitStatus> {
   return invoke<GitStatus>("open_repository", { path });
 }
 
+export function openRepoInExplorer(path: string): Promise<void> {
+  return invoke<void>("open_repo_in_explorer", { path });
+}
+
 export function openRepositoryBundle(path: string, commitLimit = 100): Promise<RepositoryBundle> {
   return invoke<RepositoryBundle>("open_repository_bundle", { path, commitLimit });
 }