add auto-updater and git workflow enhancements

This change introduces a comprehensive auto-update mechanism for the application and significant improvements to the integrated Git client experience.

Key features include:
- **Automated Release Workflow:** A new Gitea Actions workflow (`app_builder.yaml`) and a Python `cicd_tool` are added to automatically build, sign, and upload release artifacts to S3-compatible storage (MinIO) upon a new release. This also generates the `latest.json` file required by the updater.
- **Tauri Updater Integration:** The `tauri-plugin-updater` is integrated into the application, enabling it to check for and apply updates seamlessly.
- **Robust Git Push Handling:** The application now intelligently handles non-fast-forward push failures by prompting the user to perform a pull/merge operation before re-attempting the push.
- **Enhanced File Comparison:** A new `compare_file_to_parent` command is introduced, allowing detailed file diffs against a commit's direct parent, including the "empty tree" for initial commits.
- **Explorer Panel Improvements:** "Expand All" and "Collapse All" functionality is added to the file explorer for better navigation.

src/App.svelte

@@ -22,7 +22,7 @@
     compareCommits,
     cancelCodeSearch,
     diffFileAgainstWorkingTree,
-    compareFileToHead,
+    compareFileToParent,
     getStatus,
     listBranches,
     listCommits,
@@ -181,6 +181,18 @@
     try { return JSON.stringify(error) ?? "Unknown error"; } catch { return "Unknown error"; }
   }
 
+  function isNonFastForwardPushError(message: string): boolean {
+    const value = message.toLowerCase();
+    return value.includes("non-fast-forward")
+      || value.includes("failed to push some refs")
+      || value.includes("tip of your current branch is behind")
+      || value.includes("fetch first");
+  }
+
+  function statusHasConflicts(value: GitStatus | null): boolean {
+    return (value?.files ?? []).some((file) => file.staged === "conflicted" || file.unstaged === "conflicted");
+  }
+
   async function runOperation(label: string, task: () => Promise<void>) {
     if (isBusy) return;
     operation = label;
@@ -201,13 +213,17 @@
     });
   }
 
-  function defaultExpandedExplorerPaths(files: GitRepositoryFile[]): Set<string> {
-    const expanded = new Set<string>();
+  function allExplorerFolderPaths(files: GitRepositoryFile[]): Set<string> {
+    const folders = new Set<string>();
     for (const file of files) {
       const parts = file.path.split(/[\\/]+/).filter(Boolean);
-      if (parts.length > 1) expanded.add(parts[0]);
+      let currentPath = "";
+      for (let index = 0; index < parts.length - 1; index++) {
+        currentPath = currentPath ? `${currentPath}/${parts[index]}` : parts[index];
+        folders.add(currentPath);
+      }
     }
-    return expanded;
+    return folders;
   }
 
   // ── Refresh helpers ────────────────────────────────────────────────────────
@@ -231,7 +247,8 @@
 
   async function refreshExplorerFiles(path = activeRepoPath) {
     repoFiles = await listRepositoryFiles(path);
-    if (expandedExplorerPaths.size === 0) expandedExplorerPaths = defaultExpandedExplorerPaths(repoFiles);
+    const folderPaths = allExplorerFolderPaths(repoFiles);
+    expandedExplorerPaths = new Set([...expandedExplorerPaths].filter((folder) => folderPaths.has(folder)));
     if (selectedExplorerPath && !explorerPathExists(repoFiles, selectedExplorerPath)) {
       selectedExplorerPath = "";
       selectedExplorerKind = "file";
@@ -405,6 +422,50 @@
       await refreshCommitHistory(activeRepoPath);
       await refreshFileHistory(activeRepoPath);
     });
+
+    if (errorMessage && !isAuthError(errorMessage) && isNonFastForwardPushError(errorMessage)) {
+      errorMessage = "";
+      const shouldSync = window.confirm(
+        "Der Remote hat neuere Commits, deshalb wurde der Push abgelehnt.\n\nJetzt Pull/Merge ausfuehren und danach den Push erneut versuchen?",
+      );
+
+      if (!shouldSync) {
+        const message = "Push abgelehnt: Der Remote hat neuere Commits. Pull zuerst ausfuehren, dann erneut pushen.";
+        if (fromStore) errorMessage = message;
+        else credDialogError = message;
+        return;
+      }
+
+      if (!fromStore) credDialogError = "";
+
+      await runOperation("Pulling before push", async () => {
+        applyStatus(await pull(activeRepoPath, username, password));
+        await refreshBranchList(activeRepoPath);
+        await refreshCommitHistory(activeRepoPath);
+        await refreshExplorerFiles(activeRepoPath);
+        await refreshFileHistory(activeRepoPath);
+      });
+
+      if (errorMessage) {
+        handleRemoteResult("pull", key, fromStore);
+        return;
+      }
+
+      if (statusHasConflicts(status)) {
+        credDialogOpen = false;
+        credDialogAction = null;
+        errorMessage = "Pull hat Merge-Konflikte erzeugt. Loese die Konflikte, committe den Merge und pushe danach erneut.";
+        return;
+      }
+
+      await runOperation("Pushing after pull", async () => {
+        applyStatus(await push(activeRepoPath, username, password));
+        await refreshBranchList(activeRepoPath);
+        await refreshCommitHistory(activeRepoPath);
+        await refreshFileHistory(activeRepoPath);
+      });
+    }
+
     handleRemoteResult("push", key, fromStore);
   }
 
@@ -541,7 +602,7 @@
   async function previewCommitFileFromHistory(target: GitCommit, file: GitCommitFile) {
     if (!activeRepoPath) return;
     await runOperation(`Diffing ${file.path}`, async () => {
-      const result = await compareFileToHead(activeRepoPath, target.hash, file.path);
+      const result = await compareFileToParent(activeRepoPath, target.hash, file.path, file.old_path);
       const matchingFile = result.files.find((diffFile) =>
         diffFile.path === file.path || diffFile.old_path === file.old_path || diffFile.old_path === file.path,
       );
@@ -561,6 +622,14 @@
     expandedExplorerPaths = next;
   }
 
+  function expandAllExplorerFolders() {
+    expandedExplorerPaths = allExplorerFolderPaths(repoFiles);
+  }
+
+  function collapseAllExplorerFolders() {
+    expandedExplorerPaths = new Set();
+  }
+
   async function selectExplorerNode(node: ExplorerNode) {
     if (!activeRepoPath || (selectedExplorerPath === node.path && selectedExplorerKind === node.kind)) return;
     selectedExplorerPath = node.path;
@@ -845,6 +914,8 @@
           {hasRepository}
           {isBusy}
           onToggleFolder={toggleExplorerFolder}
+          onExpandAllFolders={expandAllExplorerFolders}
+          onCollapseAllFolders={collapseAllExplorerFolders}
           onSelectNode={selectExplorerNode}
         />
       </aside>