feat(clone): add repository cloning flow to UI and backend

This introduces a new Tauri command to clone a remote repository into a
validated destination folder, then return the full repository bundle for
immediate rendering. The Svelte app gains a clone dialog and a new action
in repository management, wiring the cloned bundle into existing refresh
helpers. Dialog backdrops were also adjusted to rely on explicit close
controls.

- Add clone_repository command and core cloning logic in Rust
- Create CloneRepositoryDialog and integrate it into App.svelte
- Improve clone-related styling and tighten dialog backdrop behavior

src/App.svelte

@@ -2,12 +2,13 @@
   import { onDestroy, onMount, tick } from "svelte";
   import { open as openDialog } from "@tauri-apps/plugin-dialog";
   import { check, type DownloadEvent, type Update } from "@tauri-apps/plugin-updater";
-  import { AlertCircle, BookOpen, FolderOpen, GitBranch, GitMerge, LoaderCircle, Plus, Search, X } from "@lucide/svelte";
+  import { AlertCircle, BookOpen, Download, FolderOpen, GitBranch, GitMerge, LoaderCircle, Plus, Search, X } from "@lucide/svelte";
 
   import TitleBar from "./lib/TitleBar.svelte";
   import AiSettingsDialog from "./lib/components/AiSettingsDialog.svelte";
   import BranchDeleteConfirmDialog from "./lib/components/BranchDeleteConfirmDialog.svelte";
   import BranchPanel from "./lib/components/BranchPanel.svelte";
+  import CloneRepositoryDialog from "./lib/components/CloneRepositoryDialog.svelte";
   import CommitPanel from "./lib/components/CommitPanel.svelte";
   import CompareDialog from "./lib/components/CompareDialog.svelte";
   import CompareSelectDialog from "./lib/components/CompareSelectDialog.svelte";
@@ -28,6 +29,7 @@
 
   import {
     checkoutBranch,
+    cloneRepository,
     commit,
     commitAiGenerate,
     commitAiLoad,
@@ -144,6 +146,8 @@
   let repoTabs: RepoTab[] = [];
   let recentRepoPaths: string[] = [];
   let repoSearch = "";
+  let cloneDialogOpen = false;
+  let cloneDialogError = "";
   let status: GitStatus | null = null;
   let branches: GitBranchInfo[] = [];
   let stashes: GitStash[] = [];
@@ -983,6 +987,40 @@
     }
   }
 
+  async function cloneRepo(remoteUrl: string, parentPath: string, directoryName: string) {
+    if (isBusy) return;
+    if (!remoteUrl) { errorMessage = "Enter a remote URL."; return; }
+    if (!parentPath) { errorMessage = "Select a destination folder."; return; }
+
+    operation = "Cloning repository";
+    errorMessage = "";
+    cloneDialogError = "";
+    try {
+      const bundle = await cloneRepository(remoteUrl, parentPath, directoryName || undefined, 100);
+      resetRepositoryState(false);
+      applyStatus(bundle.status);
+      if (globalSearchBusy) void cancelGlobalSearch();
+      activeView = "repository";
+      await refreshBranchList(activeRepoPath, bundle.branches);
+      await refreshStashes(activeRepoPath, bundle.stashes);
+      await refreshCommitHistory(activeRepoPath, bundle.commits);
+      await refreshExplorerFiles(activeRepoPath, bundle.files);
+      cloneDialogOpen = false;
+      lastRepoSwitchAt = Date.now();
+    } catch (error) {
+      cloneDialogError = errorToMessage(error);
+      errorMessage = cloneDialogError;
+    } finally {
+      operation = "";
+    }
+  }
+
+  function openCloneDialog() {
+    if (isBusy) return;
+    cloneDialogError = "";
+    cloneDialogOpen = true;
+  }
+
   function openRepoManagement() {
     if (isBusy) return;
     activeView = "management";
@@ -2060,6 +2098,10 @@
             <h1>Repositories</h1>
           </div>
           <div class="repo-management-actions">
+            <button class="btn-primary" type="button" onclick={openCloneDialog} disabled={isBusy}>
+              <Download size={15} aria-hidden="true" />
+              Clone
+            </button>
             <button class="btn-secondary" type="button" onclick={chooseRepositoryFolder} disabled={isBusy}>
               <FolderOpen size={15} aria-hidden="true" />
               Browse
@@ -2472,6 +2514,16 @@
   />
 {/if}
 
+<!-- Clone repository dialog -->
+{#if cloneDialogOpen}
+  <CloneRepositoryDialog
+    isBusy={operation === "Cloning repository"}
+    error={cloneDialogError}
+    onClone={cloneRepo}
+    onClose={() => { if (!isBusy) cloneDialogOpen = false; }}
+  />
+{/if}
+
 <!-- Full-screen overlay while a repository is being opened -->
 {#if openingRepo}
   <RepoLoadingOverlay repoName={repoDisplayName} />