feat(git stash): add stash listing and push/apply/pop/drop UI

This change introduces Git stash support end-to-end, including a new
backend command to list stashes and operations to push, apply, pop, and
drop them. The frontend now fetches stashes as part of the repository
bundle and provides a dedicated panel to manage shelved changes.

- Add GitStash model and Tauri commands for stash operations
- Implement StashPanel component and wire it into the app
- Adjust sidebar layout and add stash-specific styling

src/App.svelte

@@ -21,6 +21,7 @@
   import RenameBranchDialog from "./lib/components/RenameBranchDialog.svelte";
   import RepoLoadingOverlay from "./lib/components/RepoLoadingOverlay.svelte";
   import ResolveDialog from "./lib/components/ResolveDialog.svelte";
+  import StashPanel from "./lib/components/StashPanel.svelte";
   import StatusPanel from "./lib/components/StatusPanel.svelte";
   import UpdateToast from "./lib/components/UpdateToast.svelte";
 
@@ -42,6 +43,7 @@
     fetchRemote,
     getStatus,
     listBranches,
+    listStashes,
     listCommits,
     listFileHistory,
     listRepositoryFiles,
@@ -66,6 +68,10 @@
     searchCodeIntroductions,
     setSyncBadge,
     stageFiles,
+    stashApply,
+    stashDrop,
+    stashPop,
+    stashPush,
     unstageFiles,
   } from "./lib/git";
 
@@ -83,6 +89,7 @@
     GitFileStatus,
     GitRepositoryFile,
     GitSearchHit,
+    GitStash,
     GitStatus,
     LocalModelOption,
     PatchApplyAction,
@@ -135,6 +142,7 @@
   let repoSearch = "";
   let status: GitStatus | null = null;
   let branches: GitBranchInfo[] = [];
+  let stashes: GitStash[] = [];
   let commits: GitCommit[] = [];
   let repoFiles: GitRepositoryFile[] = [];
   let selectedExplorerPath = "";
@@ -298,6 +306,7 @@
       const bundle = await openRepositoryBundle(activeRepoPath, 100);
       const previousHeadHash = lastFileHistoryHeadHash;
       await refreshBranchList(activeRepoPath, bundle.branches);
+      await refreshStashes(activeRepoPath, bundle.stashes);
       await refreshCommitHistory(activeRepoPath, bundle.commits);
       await refreshExplorerFiles(activeRepoPath, bundle.files);
       // File history reflects `git log`, which only changes when HEAD actually moves
@@ -744,6 +753,7 @@
       void setSyncBadge(0, 0, 0).catch(() => {});
     }
     branches = [];
+    stashes = [];
     commits = [];
     lastFileHistoryHeadHash = "";
     repoFiles = [];
@@ -835,6 +845,10 @@
     branches = prefetched ?? (await listBranches(path));
   }
 
+  async function refreshStashes(path = activeRepoPath, prefetched?: GitStash[]) {
+    stashes = prefetched ?? (await listStashes(path));
+  }
+
   async function refreshCommitHistory(path = activeRepoPath, prefetched?: GitCommit[]) {
     commits = prefetched ?? (await listCommits(path, 100));
     lastFileHistoryHeadHash = commits[0]?.hash ?? "";
@@ -929,6 +943,7 @@
       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);
       lastRepoSwitchAt = Date.now();
@@ -1006,6 +1021,7 @@
     await runOperation("Refreshing", async () => {
       applyStatus(await getStatus(activeRepoPath));
       await refreshBranchList(activeRepoPath);
+      await refreshStashes(activeRepoPath);
       await refreshCommitHistory(activeRepoPath);
       await refreshExplorerFiles(activeRepoPath);
       await refreshFileHistory(activeRepoPath);
@@ -1301,6 +1317,47 @@
     await startRemoteAction("push");
   }
 
+  async function saveStash(message: string, includeUntracked: boolean) {
+    if (!activeRepoPath || changedFiles.length === 0) return;
+    await runOperation("Stashing changes", async () => {
+      applyStatus(await stashPush(activeRepoPath, message, includeUntracked));
+      await refreshStashes(activeRepoPath);
+      await refreshExplorerFiles(activeRepoPath);
+      await refreshFileHistory(activeRepoPath);
+    });
+  }
+
+  async function applyStashEntry(stash: GitStash) {
+    if (!activeRepoPath) return;
+    await runOperation(`Applying ${stash.selector}`, async () => {
+      applyStatus(await stashApply(activeRepoPath, stash.selector));
+      await refreshStashes(activeRepoPath);
+      await refreshExplorerFiles(activeRepoPath);
+      await refreshFileHistory(activeRepoPath);
+    });
+  }
+
+  async function popStashEntry(stash: GitStash) {
+    if (!activeRepoPath) return;
+    await runOperation(`Popping ${stash.selector}`, async () => {
+      applyStatus(await stashPop(activeRepoPath, stash.selector));
+      await refreshStashes(activeRepoPath);
+      await refreshExplorerFiles(activeRepoPath);
+      await refreshFileHistory(activeRepoPath);
+    });
+  }
+
+  async function dropStashEntry(stash: GitStash) {
+    if (!activeRepoPath) return;
+    const confirmed = window.confirm(`Delete ${stash.selector}?\n\n"${stash.message || stash.selector}"`);
+    if (!confirmed) return;
+
+    await runOperation(`Dropping ${stash.selector}`, async () => {
+      applyStatus(await stashDrop(activeRepoPath, stash.selector));
+      await refreshStashes(activeRepoPath);
+    });
+  }
+
   // ── File staging / restore ─────────────────────────────────────────────────
 
   async function stageFile(file: GitFileStatus) {
@@ -2020,6 +2077,16 @@
           onRenameBranch={renameLocalBranch}
           onDeleteBranch={deleteLocalBranch}
         />
+        <StashPanel
+          {stashes}
+          changedCount={changedFiles.length}
+          {hasRepository}
+          {isBusy}
+          onPush={saveStash}
+          onApply={applyStashEntry}
+          onPop={popStashEntry}
+          onDrop={dropStashEntry}
+        />
         <ExplorerPanel
           {repoFiles}
           {expandedExplorerPaths}