fix: update _Sidebar.md on wiki page create/delete

When creating a wiki page, add [[PageName]] to _Sidebar.md.
When deleting a wiki page, remove [[PageName]] from _Sidebar.md.
This ensures the web UI properly reflects page changes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

shortcuts/wiki/wiki.go

@@ -297,6 +297,46 @@ func runView(ctx *common.RuntimeContext) error {
 	return ctx.Output(output.SuccessEnvelope(data, nil))
 }
 
+// addSidebarLink adds a page reference to _Sidebar.md (if it exists).
+func addSidebarLink(tmpDir, pageName string) error {
+	sidebarPath := filepath.Join(tmpDir, "_Sidebar.md")
+	entry := fmt.Sprintf("[[%s]]", pageName)
+	content, err := os.ReadFile(sidebarPath)
+	if err != nil {
+		// If _Sidebar.md doesn't exist, create it
+		return os.WriteFile(sidebarPath, []byte(entry+"\n"), 0644)
+	}
+	if strings.Contains(string(content), entry) {
+		return nil // already present
+	}
+	// Append entry
+	f, err := os.OpenFile(sidebarPath, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = f.WriteString(entry + "\n")
+	return err
+}
+
+// removeSidebarLink removes a page reference from _Sidebar.md (if it exists).
+func removeSidebarLink(tmpDir, pageName string) error {
+	sidebarPath := filepath.Join(tmpDir, "_Sidebar.md")
+	content, err := os.ReadFile(sidebarPath)
+	if err != nil {
+		return nil // no sidebar to update
+	}
+	entry := fmt.Sprintf("[[%s]]", pageName)
+	lines := strings.Split(string(content), "\n")
+	var newLines []string
+	for _, line := range lines {
+		if strings.TrimSpace(line) != entry {
+			newLines = append(newLines, line)
+		}
+	}
+	return os.WriteFile(sidebarPath, []byte(strings.Join(newLines, "\n")+"\n"), 0644)
+}
+
 func runCreate(ctx *common.RuntimeContext) error {
 	if err := ctx.ResolveOwnerRepo(); err != nil {
 		return err
@@ -411,6 +451,10 @@ func runUpdate(ctx *common.RuntimeContext) error {
 			return fmt.Errorf("write page: %w", err)
 		}
 	} else if title := ctx.Arg("title"); title != "" {
+		// Update sidebar
+		if err := addSidebarLink(tmpDir, pageName); err != nil {
+			return fmt.Errorf("update sidebar: %w", err)
+		}
 		// Only updating title: read existing content and replace/re-add the heading
 		existing, err := os.ReadFile(filePath)
 		if err != nil {
@@ -488,6 +532,10 @@ func runDelete(ctx *common.RuntimeContext) error {
 		return fmt.Errorf("page %q not found", pageName)
 	}
 
+	// Remove from sidebar
+	if err := removeSidebarLink(tmpDir, pageName); err != nil {
+		return fmt.Errorf("update sidebar: %w", err)
+	}
 	if err := os.Remove(filePath); err != nil {
 		return fmt.Errorf("delete page: %w", err)
 	}
@@ -497,7 +545,7 @@ func runDelete(ctx *common.RuntimeContext) error {
 		msg = fmt.Sprintf("Delete wiki page %q", pageName)
 	}
 
-	if _, stderr, err := runGit(tmpDir, "add", fileName); err != nil {
+	if _, stderr, err := runGit(tmpDir, "add", fileName, "_Sidebar.md"); err != nil {
 		return fmt.Errorf("git add: %s%s", stderr, err)
 	}
 	if _, stderr, err := runGit(tmpDir, "commit", "-m", msg); err != nil {