feat(update): add Release/Nightly channel switching

- Add POST /api/lm/switch-channel endpoint with git init / ZIP fallback
- Add _backup_git/_restore_git helpers with safe rollback
- Version-info endpoint now returns has_git flag for auto-detection
- Check-updates always returns releases (changelog) regardless of channel
- Nightly mode shows 'N commits behind main' with commit hash and date
- View on GitHub link points to /commits/main in nightly mode
- Channel toggle UI with pill-style buttons in update modal
- Confirmation dialog with Esc / backdrop-dismiss support
- Channel derived from has_git on every page load, no localStorage
- i18n: 11 new keys translated across 9 non-English locales
- CSS: unified card-style sections in _base.css
- Tests: 8 new tests covering switch-channel, nightly response, init_git_repo

locales/de.json

@@ -1752,6 +1752,12 @@
     "checkingMessage": "Bitte warten Sie, während wir nach der neuesten Version suchen.",
     "showNotifications": "Update-Benachrichtigungen anzeigen",
     "latestBadge": "Neueste",
+    "latestMain": "Main-Branch",
+    "channel": "Update-Kanal",
+    "channels": {
+      "release": "Release",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "Update wird vorbereitet...",
       "installing": "Update wird installiert...",
@@ -1772,6 +1778,15 @@
       "warning": "Warnung: Nightly Builds können experimentelle Funktionen enthalten und könnten instabil sein.",
       "enable": "Nightly Updates aktivieren"
     },
+    "channelSwitch": {
+      "nightlyTitle": "Zu Nightly-Kanal wechseln",
+      "nightlyMessage": "Der Wechsel zu Nightly initialisiert ein Git-Repository und verfolgt die neuesten Commits des main-Branches. Updates sind häufiger, können aber instabil sein. Sie können jederzeit zu Release zurückwechseln.",
+      "releaseTitle": "Zu Release-Kanal wechseln",
+      "releaseMessage": "Der Wechsel zu Release entfernt das Git-Repository und installiert die neueste stabile Version. Zukünftige Updates verwenden nur stabile Versionen.",
+      "switching": "Wechsle zu {channel}-Kanal...",
+      "completed": "Erfolgreich zu {channel}-Kanal gewechselt",
+      "failed": "Kanalwechsel fehlgeschlagen"
+    },
     "banners": {
       "recent": "Neueste Mitteilungen",
       "empty": "Keine aktuellen Banner verfügbar.",
@@ -2235,4 +2250,4 @@
       "retry": "Wiederholen"
     }
   }
-}
+}

locales/en.json

@@ -1752,6 +1752,12 @@
     "checkingMessage": "Please wait while we check for the latest version.",
     "showNotifications": "Show update notifications",
     "latestBadge": "Latest",
+    "latestMain": "Latest main",
+    "channel": "Update Channel",
+    "channels": {
+      "release": "Release",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "Preparing update...",
       "installing": "Installing update...",
@@ -1772,6 +1778,15 @@
       "warning": "Warning: Nightly builds may contain experimental features and could be unstable.",
       "enable": "Enable Nightly Updates"
     },
+    "channelSwitch": {
+      "nightlyTitle": "Switch to Nightly Channel",
+      "nightlyMessage": "Switching to Nightly will initialize a Git repository and track the latest main branch commits. Updates will be more frequent but may be unstable. You can switch back to Release at any time.",
+      "releaseTitle": "Switch to Release Channel",
+      "releaseMessage": "Switching to Release will remove the Git repository and install the latest stable release. Future updates will use stable releases only.",
+      "switching": "Switching to {channel} channel...",
+      "completed": "Successfully switched to {channel} channel",
+      "failed": "Failed to switch channel"
+    },
     "banners": {
       "recent": "Recent messages",
       "empty": "No recent banners yet.",

locales/es.json

@@ -1751,7 +1751,13 @@
     "checkingUpdates": "Comprobando actualizaciones...",
     "checkingMessage": "Por favor espera mientras comprobamos la última versión.",
     "showNotifications": "Mostrar notificaciones de actualización",
-    "latestBadge": "Último",
+    "latestBadge": "Última",
+    "latestMain": "Rama main",
+    "channel": "Canal de actualizacion",
+    "channels": {
+      "release": "Release",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "Preparando actualización...",
       "installing": "Instalando actualización...",
@@ -1772,6 +1778,15 @@
       "warning": "Advertencia: Las compilaciones nocturnas pueden contener características experimentales y podrían ser inestables.",
       "enable": "Habilitar actualizaciones nocturnas"
     },
+    "channelSwitch": {
+      "nightlyTitle": "Cambiar a canal Nightly",
+      "nightlyMessage": "Cambiar a Nightly inicializara un repositorio Git y seguira los ultimos commits de la rama main. Las actualizaciones son mas frecuentes pero pueden ser inestables. Puede volver a Release en cualquier momento.",
+      "releaseTitle": "Cambiar a canal Release",
+      "releaseMessage": "Cambiar a Release eliminara el repositorio Git e instalara la ultima version estable. Las futuras actualizaciones usaran solo versiones estables.",
+      "switching": "Cambiando a canal {channel}...",
+      "completed": "Cambio a canal {channel} exitoso",
+      "failed": "Error al cambiar de canal"
+    },
     "banners": {
       "recent": "Notificaciones recientes",
       "empty": "No hay banners recientes.",
@@ -2235,4 +2250,4 @@
       "retry": "Reintentar"
     }
   }
-}
+}

locales/fr.json

@@ -1751,7 +1751,13 @@
     "checkingUpdates": "Vérification des mises à jour...",
     "checkingMessage": "Veuillez patienter pendant la vérification de la dernière version.",
     "showNotifications": "Afficher les notifications de mise à jour",
-    "latestBadge": "Dernier",
+    "latestBadge": "Dernière",
+    "latestMain": "Branche main",
+    "channel": "Canal de mise a jour",
+    "channels": {
+      "release": "Release",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "Préparation de la mise à jour...",
       "installing": "Installation de la mise à jour...",
@@ -1772,6 +1778,15 @@
       "warning": "Attention : Les versions nightly peuvent contenir des fonctionnalités expérimentales et être instables.",
       "enable": "Activer les mises à jour nightly"
     },
+    "channelSwitch": {
+      "nightlyTitle": "Passer au canal Nightly",
+      "nightlyMessage": "Passer a Nightly initialisera un depot Git et suivra les derniers commits de la branche main. Les mises a jour sont plus frequentes mais peuvent etre instables. Vous pouvez revenir a Release a tout moment.",
+      "releaseTitle": "Passer au canal Release",
+      "releaseMessage": "Passer a Release supprimera le depot Git et installera la derniere version stable. Les futures mises a jour utiliseront uniquement des versions stables.",
+      "switching": "Passage au canal {channel}...",
+      "completed": "Basculement vers le canal {channel} reussi",
+      "failed": "Echec du changement de canal"
+    },
     "banners": {
       "recent": "Messages récents",
       "empty": "Aucune bannière récente.",
@@ -2235,4 +2250,4 @@
       "retry": "Réessayer"
     }
   }
-}
+}

locales/he.json

@@ -1751,7 +1751,13 @@
     "checkingUpdates": "בודק עדכונים...",
     "checkingMessage": "אנא המתן בזמן שאנו בודקים את הגרסה האחרונה.",
     "showNotifications": "הצג התראות עדכון",
-    "latestBadge": "עדכן",
+    "latestBadge": "אחרון",
+    "latestMain": "ענף main",
+    "channel": "ערוץ עדכון",
+    "channels": {
+      "release": "Release",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "מכין עדכון...",
       "installing": "מתקין עדכון...",
@@ -1772,6 +1778,15 @@
       "warning": "אזהרה: גרסאות ליליות עשויות להכיל תכונות ניסיוניות ועלולות להיות לא יציבות.",
       "enable": "הפעל עדכונים ליליים"
     },
+    "channelSwitch": {
+      "nightlyTitle": "מעבר לערוץ Nightly",
+      "nightlyMessage": "מעבר ל-Nightly יאתחל מאגר Git ויעקוב אחר הקומיטים האחרונים בענף main. העדכונים תכופים יותר אך עשויים להיות לא יציבים. ניתן לחזור ל-Release בכל עת.",
+      "releaseTitle": "מעבר לערוץ Release",
+      "releaseMessage": "מעבר ל-Release יסיר את מאגר ה-Git ויתקין את הגרסה היציבה האחרונה. עדכונים עתידיים ישתמשו בגרסאות יציבות בלבד.",
+      "switching": "מעבר לערוץ {channel}...",
+      "completed": "המעבר לערוץ {channel} הושלם",
+      "failed": "החלפת ערוץ נכשלה"
+    },
     "banners": {
       "recent": "הודעות אחרונות",
       "empty": "אין כרגע באנרים אחרונים.",
@@ -2235,4 +2250,4 @@
       "retry": "נסה שוב"
     }
   }
-}
+}

locales/ja.json

@@ -1752,6 +1752,12 @@
     "checkingMessage": "最新バージョンを確認しています。お待ちください。",
     "showNotifications": "更新通知を表示",
     "latestBadge": "最新",
+    "latestMain": "Main ブランチ",
+    "channel": "更新チャンネル",
+    "channels": {
+      "release": "リリース",
+      "nightly": "ナイトリー"
+    },
     "updateProgress": {
       "preparing": "更新を準備中...",
       "installing": "更新をインストール中...",
@@ -1772,6 +1778,15 @@
       "warning": "警告：ナイトリービルドには実験的機能が含まれており、不安定な場合があります。",
       "enable": "ナイトリー更新を有効にする"
     },
+    "channelSwitch": {
+      "nightlyTitle": "ナイトリーチャンネルに切り替え",
+      "nightlyMessage": "ナイトリーに切り替えると、Gitリポジトリが初期化され、mainブランチの最新コミットを追跡します。更新頻度は高くなりますが、不安定な場合があります。いつでもリリース版に戻せます。",
+      "releaseTitle": "リリースチャンネルに切り替え",
+      "releaseMessage": "リリースに切り替えると、Gitリポジトリが削除され、最新の安定版がインストールされます。以降の更新は安定版のみが使用されます。",
+      "switching": "{channel} チャンネルに切り替え中...",
+      "completed": "{channel} チャンネルに切り替えました",
+      "failed": "チャンネルの切り替えに失敗しました"
+    },
     "banners": {
       "recent": "最近の通知",
       "empty": "最近のバナーはありません。",
@@ -2235,4 +2250,4 @@
       "retry": "再試行"
     }
   }
-}
+}

locales/ko.json

@@ -1752,6 +1752,12 @@
     "checkingMessage": "최신 버전을 확인하는 동안 잠시 기다려주세요.",
     "showNotifications": "업데이트 알림 표시",
     "latestBadge": "최신",
+    "latestMain": "Main 브랜치",
+    "channel": "업데이트 채널",
+    "channels": {
+      "release": "릴리스",
+      "nightly": "나이틀리"
+    },
     "updateProgress": {
       "preparing": "업데이트 준비 중...",
       "installing": "업데이트 설치 중...",
@@ -1772,6 +1778,15 @@
       "warning": "경고: 나이틀리 빌드는 실험적 기능을 포함할 수 있으며 불안정할 수 있습니다.",
       "enable": "나이틀리 업데이트 활성화"
     },
+    "channelSwitch": {
+      "nightlyTitle": "나이틀리 채널로 전환",
+      "nightlyMessage": "나이틀리로 전환하면 Git 저장소가 초기화되고 main 브랜치의 최신 커밋을 추적합니다. 업데이트 빈도는 높지만 불안정할 수 있습니다. 언제든지 릴리스로 돌아갈 수 있습니다.",
+      "releaseTitle": "릴리스 채널로 전환",
+      "releaseMessage": "릴리스로 전환하면 Git 저장소가 제거되고 최신 안정 버전이 설치됩니다. 이후 업데이트는 안정 버전만 사용됩니다.",
+      "switching": "{channel} 채널로 전환 중...",
+      "completed": "{channel} 채널로 전환 완료",
+      "failed": "채널 전환 실패"
+    },
     "banners": {
       "recent": "최근 알림",
       "empty": "최근 배너가 없습니다.",
@@ -2235,4 +2250,4 @@
       "retry": "다시 시도"
     }
   }
-}
+}

locales/ru.json

@@ -1751,7 +1751,13 @@
     "checkingUpdates": "Проверка обновлений...",
     "checkingMessage": "Пожалуйста, подождите, пока мы проверяем последнюю версию.",
     "showNotifications": "Показывать уведомления об обновлениях",
-    "latestBadge": "Последний",
+    "latestBadge": "Последняя",
+    "latestMain": "Ветка main",
+    "channel": "Канал обновлений",
+    "channels": {
+      "release": "Релиз",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "Подготовка обновления...",
       "installing": "Установка обновления...",
@@ -1772,6 +1778,15 @@
       "warning": "Предупреждение: Ночные сборки могут содержать экспериментальные функции и могут быть нестабильными.",
       "enable": "Включить ночные обновления"
     },
+    "channelSwitch": {
+      "nightlyTitle": "Переключиться на Nightly",
+      "nightlyMessage": "Переключение на Nightly инициализирует Git-репозиторий и отслеживает последние коммиты ветки main. Обновления чаще, но могут быть нестабильными. Вы можете вернуться к Release в любое время.",
+      "releaseTitle": "Переключиться на Release",
+      "releaseMessage": "Переключение на Release удалит Git-репозиторий и установит последнюю стабильную версию. Будущие обновления будут использовать только стабильные версии.",
+      "switching": "Переключение на канал {channel}...",
+      "completed": "Успешно переключено на канал {channel}",
+      "failed": "Не удалось переключить канал"
+    },
     "banners": {
       "recent": "Недавние уведомления",
       "empty": "Недавних баннеров нет.",
@@ -2235,4 +2250,4 @@
       "retry": "Повторить"
     }
   }
-}
+}

locales/zh-CN.json

@@ -1752,6 +1752,12 @@
     "checkingMessage": "请稍候，正在检查最新版本。",
     "showNotifications": "显示更新通知",
     "latestBadge": "最新",
+    "latestMain": "Main 分支",
+    "channel": "更新频道",
+    "channels": {
+      "release": "稳定版",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "正在准备更新...",
       "installing": "正在安装更新...",
@@ -1772,6 +1778,15 @@
       "warning": "警告：Nightly 版本可能包含实验性功能，可能不稳定。",
       "enable": "启用 Nightly 更新"
     },
+    "channelSwitch": {
+      "nightlyTitle": "切换到 Nightly",
+      "nightlyMessage": "切换到 Nightly 将初始化 Git 仓库并跟踪 main 分支的最新提交。更新更频繁但可能不稳定，可随时切回稳定版。",
+      "releaseTitle": "切换到稳定版",
+      "releaseMessage": "切换到稳定版将移除 Git 仓库并安装最新的稳定发布版本，后续仅使用稳定版更新。",
+      "switching": "正在切换到 {channel} 频道...",
+      "completed": "已切换到 {channel} 频道",
+      "failed": "切换频道失败"
+    },
     "banners": {
       "recent": "最近的通知",
       "empty": "暂无最近的横幅通知。",
@@ -2235,4 +2250,4 @@
       "retry": "重试"
     }
   }
-}
+}

locales/zh-TW.json

@@ -1752,6 +1752,12 @@
     "checkingMessage": "請稍候，正在檢查最新版本。",
     "showNotifications": "顯示更新通知",
     "latestBadge": "最新",
+    "latestMain": "Main 分支",
+    "channel": "更新頻道",
+    "channels": {
+      "release": "稳定版",
+      "nightly": "Nightly"
+    },
     "updateProgress": {
       "preparing": "正在準備更新...",
       "installing": "正在安裝更新...",
@@ -1772,6 +1778,15 @@
       "warning": "警告：Nightly 版本可能包含實驗性功能且可能不穩定。",
       "enable": "啟用 Nightly 更新"
     },
+    "channelSwitch": {
+      "nightlyTitle": "切换到 Nightly",
+      "nightlyMessage": "切换到 Nightly 将初始化 Git 仓库并跟踪 main 分支的最新提交。更新更频繁但可能不稳定，可随时切回稳定版。",
+      "releaseTitle": "切换到稳定版",
+      "releaseMessage": "切换到稳定版将移除 Git 仓库并安装最新的稳定发布版本，后续仅使用稳定版更新。",
+      "switching": "正在切換到 {channel} 頻道...",
+      "completed": "已切換到 {channel} 頻道",
+      "failed": "切換頻道失敗"
+    },
     "banners": {
       "recent": "最新通知",
       "empty": "目前沒有最近的橫幅通知。",
@@ -2235,4 +2250,4 @@
       "retry": "重試"
     }
   }
-}
+}

py/routes/update_routes.py

@@ -47,6 +47,7 @@ class UpdateRoutes:
         app.router.add_get('/api/lm/check-updates', UpdateRoutes.check_updates)
         app.router.add_get('/api/lm/version-info', UpdateRoutes.get_version_info)
         app.router.add_post('/api/lm/perform-update', UpdateRoutes.perform_update)
+        app.router.add_post('/api/lm/switch-channel', UpdateRoutes.switch_channel)
     
     @staticmethod
     async def check_updates(request):
@@ -65,10 +66,17 @@ class UpdateRoutes:
 
             # Fetch remote version from GitHub
             if nightly:
-                remote_version, changelog = await UpdateRoutes._get_nightly_version()
+                local_hash = git_info.get('short_hash', '')
-                releases = None
+                nightly_version, releases_result = await asyncio.gather(
+                    UpdateRoutes._get_nightly_version(local_hash),
+                    UpdateRoutes._get_remote_version()
+                )
+                remote_version, _, behind_by, commit_date = nightly_version
+                _, changelog, releases = releases_result
             else:
                 remote_version, changelog, releases = await UpdateRoutes._get_remote_version()
+                behind_by = 0
+                commit_date = ''
             
             # Compare versions
             if nightly:
@@ -81,6 +89,10 @@ class UpdateRoutes:
                     remote_version.replace('v', '')
                 )
             
+            current_dir = os.path.dirname(os.path.abspath(__file__))
+            plugin_root = os.path.dirname(os.path.dirname(current_dir))
+            has_git = os.path.exists(os.path.join(plugin_root, '.git'))
+
             response_data = {
                 'success': True,
                 'current_version': local_version,
@@ -88,13 +100,13 @@ class UpdateRoutes:
                 'update_available': update_available,
                 'changelog': changelog,
                 'git_info': git_info,
-                'nightly': nightly
+                'nightly': nightly,
+                'has_git': has_git,
+                'releases': releases,
+                'behind_by': behind_by,
+                'commit_date': commit_date
             }
             
-            # Include releases list for stable mode
-            if releases is not None:
-                response_data['releases'] = releases
-            
             return web.json_response(response_data)
             
         except NETWORK_EXCEPTIONS as e:
@@ -126,9 +138,14 @@ class UpdateRoutes:
             # Format: version-short_hash
             version_string = f"{local_version}-{short_hash}"
             
+            current_dir = os.path.dirname(os.path.abspath(__file__))
+            plugin_root = os.path.dirname(os.path.dirname(current_dir))
+            has_git = os.path.exists(os.path.join(plugin_root, '.git'))
+
             return web.json_response({
                 'success': True,
-                'version': version_string
+                'version': version_string,
+                'has_git': has_git
             })
             
         except Exception as e:
@@ -190,6 +207,162 @@ class UpdateRoutes:
                 'error': str(e)
             })
 
+    @staticmethod
+    async def switch_channel(request):
+        """
+        Switch between release and nightly update channels.
+        
+        Release → Nightly: Initialize a Git repository (from ZIP/CM stable mode)
+        Nightly → Release: Remove .git, download latest release ZIP, write .tracking
+        """
+        try:
+            body = await request.json() if request.has_body else {}
+            channel = body.get('channel', '')
+
+            if channel not in ('release', 'nightly'):
+                return web.json_response({
+                    'success': False,
+                    'error': f'Invalid channel: {channel}. Must be "release" or "nightly".'
+                })
+
+            current_dir = os.path.dirname(os.path.abspath(__file__))
+            plugin_root = os.path.dirname(os.path.dirname(current_dir))
+
+            settings_path = ensure_settings_file(logger)
+            settings_backup = None
+            if os.path.exists(settings_path):
+                with open(settings_path, 'r', encoding='utf-8') as f:
+                    settings_backup = f.read()
+                logger.info("Backed up settings.json before channel switch")
+
+            git_folder = os.path.join(plugin_root, '.git')
+
+            if channel == 'nightly':
+                git_backup = None
+                if os.path.exists(git_folder):
+                    git_backup = UpdateRoutes._backup_git(git_folder, 'nightly')
+
+                success = False
+                new_version = ''
+                try:
+                    if os.path.exists(git_folder):
+                        success, new_version = await UpdateRoutes._perform_git_update(
+                            plugin_root, nightly=True
+                        )
+                    else:
+                        success, new_version = UpdateRoutes._init_git_repo(plugin_root)
+                finally:
+                    UpdateRoutes._restore_git(git_backup, git_folder, success, 'nightly')
+            else:
+                git_backup = None
+                if os.path.exists(git_folder):
+                    git_backup = UpdateRoutes._backup_git(git_folder, 'release')
+
+                success = False
+                new_version = ''
+                try:
+                    if os.path.exists(git_folder):
+                        shutil.rmtree(git_folder)
+                    tracking_file = os.path.join(plugin_root, '.tracking')
+                    if os.path.exists(tracking_file):
+                        os.remove(tracking_file)
+                    success, new_version = await UpdateRoutes._download_and_replace_zip(plugin_root)
+                finally:
+                    UpdateRoutes._restore_git(git_backup, git_folder, success, 'release')
+
+            if settings_backup and success:
+                with open(settings_path, 'w', encoding='utf-8') as f:
+                    f.write(settings_backup)
+                logger.info("Restored settings.json after channel switch")
+
+            if success:
+                return web.json_response({
+                    'success': True,
+                    'channel': channel,
+                    'new_version': new_version,
+                    'message': f'Switched to {channel} channel'
+                })
+            else:
+                return web.json_response({
+                    'success': False,
+                    'error': f'Failed to switch to {channel} channel'
+                })
+
+        except Exception as e:
+            logger.error("Failed to switch channel: %s", e, exc_info=True)
+            return web.json_response({
+                'success': False,
+                'error': str(e)
+            })
+
+    @staticmethod
+    def _init_git_repo(plugin_root: str) -> tuple[bool, str]:
+        """
+        Initialize a Git repository in a ZIP-installed plugin folder.
+        Clones the remote history and checks out main branch.
+        """
+        try:
+            import git
+        except ImportError:
+            logger.error(
+                "GitPython is not available: cannot initialize git repo. "
+                "Install git or set $GIT_PYTHON_GIT_EXECUTABLE to the git binary path."
+            )
+            return False, ""
+
+        clean_excludes = _clean_excludes()
+
+        try:
+            repo = git.Repo.init(plugin_root)
+            origin = repo.create_remote(
+                'origin',
+                'https://github.com/willmiao/ComfyUI-Lora-Manager.git'
+            )
+            origin.fetch()
+
+            repo.create_head('main', origin.refs.main)
+            repo.git.checkout('main', '--force')
+            repo.git.reset('--hard')
+            repo.git.clean('-fd', *clean_excludes)
+
+            tracking_file = os.path.join(plugin_root, '.tracking')
+            if os.path.exists(tracking_file):
+                os.remove(tracking_file)
+                logger.info("Removed .tracking file (now in git mode)")
+
+            new_version = f"main-{repo.head.commit.hexsha[:7]}"
+            logger.info("Initialized git repo on main branch: %s", new_version)
+            return True, new_version
+
+        except Exception as e:
+            logger.error("Failed to initialize git repo: %s", e, exc_info=True)
+            return False, ""
+
+    @staticmethod
+    def _backup_git(git_folder, label):
+        try:
+            backup_dir = tempfile.mkdtemp()
+            backup = os.path.join(backup_dir, '.git')
+            shutil.copytree(git_folder, backup)
+            logger.info("Backed up .git before switching to %s", label)
+            return backup
+        except Exception as e:
+            logger.error("Failed to backup .git before %s switch: %s", label, e)
+            return None
+
+    @staticmethod
+    def _restore_git(git_backup, git_folder, success, label):
+        if git_backup and not success:
+            try:
+                if os.path.exists(git_folder):
+                    shutil.rmtree(git_folder)
+                shutil.copytree(git_backup, git_folder)
+                logger.info("Restored .git after failed %s switch", label)
+            except Exception as e:
+                logger.error("Failed to restore .git after %s switch: %s", label, e)
+        if git_backup:
+            shutil.rmtree(os.path.dirname(git_backup), ignore_errors=True)
+
     @staticmethod
     async def _download_and_replace_zip(plugin_root: str) -> tuple[bool, str]:
         """
@@ -295,7 +468,8 @@ class UpdateRoutes:
         except Exception as e:
             logger.error(f"ZIP update failed: {e}", exc_info=True)
             return False, ""
-        
+
+    @staticmethod
     def _clean_plugin_folder(plugin_root, skip_files=None):
         skip_files = skip_files or []
         for item in os.listdir(plugin_root):
@@ -308,41 +482,51 @@ class UpdateRoutes:
                 os.remove(path)
     
     @staticmethod
-    async def _get_nightly_version() -> tuple[str, List[str]]:
+    async def _get_nightly_version(local_hash: str = "") -> tuple[str, List[str], int, str]:
-        """
-        Fetch latest commit from main branch
-        """
         repo_owner = "willmiao"
         repo_name = "ComfyUI-Lora-Manager"
-        
+
-        # Use GitHub API to fetch the latest commit from main branch
         github_url = f"https://api.github.com/repos/{repo_owner}/{repo_name}/commits/main"
-        
+
         try:
             downloader = await get_downloader()
-            success, data = await downloader.make_request('GET', github_url, custom_headers={'Accept': 'application/vnd.github+json'})
+            success, data = await downloader.make_request(
-            
+                'GET', github_url,
+                custom_headers={'Accept': 'application/vnd.github+json'}
+            )
+
             if not success:
-                logger.warning(f"Failed to fetch GitHub commit: {data}")
+                logger.warning("Failed to fetch GitHub commit: %s", data)
-                return "main", []
+                return "main", [], 0, ""
-            
+
-            commit_sha = data.get('sha', '')[:7]  # Short hash
+            commit_sha = data.get('sha', '')[:7]
             commit_message = data.get('commit', {}).get('message', '')
-            
+            commit_date = data.get('commit', {}).get('committer', {}).get('date', '')[:10]
-            # Format as "main-{short_hash}"
+
             version = f"main-{commit_sha}"
-            
-            # Use commit message as changelog
             changelog = [commit_message] if commit_message else []
-            
+
-            return version, changelog
+            behind_by = 0
-        
+            if local_hash and local_hash not in ('unknown', 'stable'):
+                compare_url = (
+                    f"https://api.github.com/repos/{repo_owner}/{repo_name}"
+                    f"/compare/{local_hash}...main"
+                )
+                c_ok, c_data = await downloader.make_request(
+                    'GET', compare_url,
+                    custom_headers={'Accept': 'application/vnd.github+json'}
+                )
+                if c_ok:
+                    behind_by = c_data.get('behind_by', 0)
+
+            return version, changelog, behind_by, commit_date
+
         except NETWORK_EXCEPTIONS as e:
             logger.warning("Unable to reach GitHub for nightly version: %s", e)
-            return "main", []
+            return "main", [], 0, ""
         except Exception as e:
-            logger.error(f"Error fetching nightly version: {e}", exc_info=True)
+            logger.error("Error fetching nightly version: %s", e, exc_info=True)
-            return "main", []
+            return "main", [], 0, ""
     
     @staticmethod
     def _compare_nightly_versions(local_git_info: Dict[str, str], remote_version: str) -> bool:

static/css/components/modal/_base.css

@@ -151,6 +151,7 @@ body.modal-open {
 .support-section,
 .changelog-section,
 .update-info,
+.update-channels,
 .info-item,
 .path-preview {
     background: var(--surface-subtle);

static/css/components/modal/update-modal.css

@@ -93,15 +93,13 @@
 .update-content {
     display: flex;
     flex-direction: column;
-    gap: var(--space-3);
+    gap: var(--space-2);
 }
 
 .update-info {
     display: flex;
     justify-content: space-between;
     align-items: center;
-    border-radius: var(--border-radius-sm);
-    padding: var(--space-3);
 }
 
 .update-info .version-info {
@@ -175,7 +173,6 @@
     border: 1px solid var(--lora-border);
     border-radius: var(--border-radius-sm);
     padding: var(--space-2);
-    margin: var(--space-2) 0;
 }
 
 [data-theme="dark"] .update-progress {
@@ -233,11 +230,6 @@
 }
 
 /* Changelog section */
-.changelog-section {
-    border-radius: var(--border-radius-sm);
-    padding: var(--space-3);
-}
-
 .changelog-section h3 {
     margin-top: 0;
     margin-bottom: var(--space-2);
@@ -349,6 +341,131 @@
     text-decoration: underline;
 }
 
+/* Channel Toggle */
+.update-channels {
+}
+
+.channels-label {
+    font-size: 0.9em;
+    color: var(--text-color);
+    opacity: 0.8;
+    margin-bottom: 8px;
+}
+
+.channel-toggle {
+    display: flex;
+    gap: 0;
+    background: var(--lora-surface);
+    border-radius: 8px;
+    padding: 3px;
+    width: fit-content;
+}
+
+.channel-btn {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    padding: 8px 20px;
+    border: none;
+    border-radius: 6px;
+    background: transparent;
+    color: var(--text-secondary, #999);
+    cursor: pointer;
+    font-size: 0.9em;
+    font-weight: 500;
+    transition: all 0.2s ease;
+    white-space: nowrap;
+}
+
+.channel-btn:hover {
+    color: var(--text-primary, #ddd);
+    background: rgba(255, 255, 255, 0.04);
+}
+
+.channel-btn.active {
+    background: var(--lora-accent, #4285F4);
+    color: #fff;
+    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
+}
+
+.channel-btn.active i {
+    color: #fff;
+}
+
+.channel-btn i {
+    font-size: 0.85em;
+}
+
+/* Channel Switch Confirmation Overlay */
+.channel-switch-overlay {
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.6);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 10000;
+    backdrop-filter: blur(2px);
+}
+
+.channel-switch-dialog {
+    background: var(--lora-surface);
+    border: 1px solid var(--border-color, rgba(255, 255, 255, 0.1));
+    border-radius: 12px;
+    padding: 28px 32px;
+    max-width: 420px;
+    width: 90%;
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
+}
+
+.channel-switch-dialog h3 {
+    margin: 0 0 12px;
+    font-size: 1.1em;
+    color: var(--text-primary, #eee);
+}
+
+.channel-switch-dialog p {
+    margin: 0 0 24px;
+    font-size: 0.9em;
+    color: var(--text-secondary, #aaa);
+    line-height: 1.6;
+}
+
+.channel-switch-actions {
+    display: flex;
+    justify-content: flex-end;
+    gap: 10px;
+}
+
+.channel-switch-cancel {
+    padding: 8px 18px;
+    border: 1px solid var(--border-color, rgba(255, 255, 255, 0.1));
+    border-radius: 6px;
+    background: transparent;
+    color: var(--text-secondary, #aaa);
+    cursor: pointer;
+    font-size: 0.9em;
+}
+
+.channel-switch-cancel:hover {
+    background: rgba(255, 255, 255, 0.04);
+}
+
+.channel-switch-confirm {
+    padding: 8px 18px;
+    border: none;
+    border-radius: 6px;
+    background: var(--lora-accent, #4285F4);
+    color: #fff;
+    cursor: pointer;
+    font-size: 0.9em;
+    font-weight: 500;
+}
+
+.channel-switch-confirm:hover {
+    opacity: 0.9;
+}
+
 /* Update preferences section */
 .update-preferences {
     border-top: 1px solid var(--lora-border);

static/js/managers/UpdateService.js

@@ -24,7 +24,9 @@ export class UpdateService {
         this.updateNotificationsEnabled = getStorageItem('show_update_notifications', true);
         this.lastCheckTime = parseInt(getStorageItem('last_update_check') || '0');
         this.isUpdating = false;
-        this.nightlyMode = getStorageItem('nightly_updates', false);
+        this.channelMode = null;
+        this.hasGit = false;
+        this.progressKeepVisible = false;
         this.currentVersionInfo = null;
         this.versionMismatch = false;
         this.activeNotificationTab = 'updates';
@@ -49,43 +51,161 @@ export class UpdateService {
             updateBtn.addEventListener('click', () => this.performUpdate());
         }
         
-        // Register event listener for nightly update toggle
+        this.wireChannelButtons();
-        const nightlyCheckbox = document.getElementById('nightlyUpdateToggle');
-        if (nightlyCheckbox) {
-            nightlyCheckbox.checked = this.nightlyMode;
-            nightlyCheckbox.addEventListener('change', (e) => {
-                this.nightlyMode = e.target.checked;
-                setStorageItem('nightly_updates', e.target.checked);
-                this.updateNightlyWarning();
-                this.updateModalContent();
-                // Re-check for updates when switching channels
-                this.manualCheckForUpdates();
-            });
-            this.updateNightlyWarning();
-        }
 
         this.setupNotificationCenter();
         window.addEventListener('lm:banner-history-updated', this.handleBannerHistoryUpdated);
         this.updateTabBadges();
         
         // Perform update check if needed
-        this.checkForUpdates().then(() => {
+        this.checkVersionInfo().then(() => {
-            // Ensure badges are updated after checking
+            if (this.channelMode === null) {
-            this.updateBadgeVisibility();
+                this.channelMode = this.hasGit ? 'nightly' : 'release';
+            }
+            this.checkForUpdates().then(() => {
+                this.updateBadgeVisibility();
+            });
         });
 
-        // Immediately update modal content with current values (even if from default)
         this.updateModalContent();
-        
-        // Check version info for mismatch after loading basic info
-        this.checkVersionInfo();
     }
     
-    updateNightlyWarning() {
+    wireChannelButtons() {
-        const warning = document.getElementById('nightlyWarning');
+        const releaseBtn = document.getElementById('channelRelease');
-        if (warning) {
+        const nightlyBtn = document.getElementById('channelNightly');
-            warning.style.display = this.nightlyMode ? 'flex' : 'none';
+        if (releaseBtn) {
+            releaseBtn.addEventListener('click', () => this.switchChannel('release'));
         }
+        if (nightlyBtn) {
+            nightlyBtn.addEventListener('click', () => this.switchChannel('nightly'));
+        }
+    }
+
+    async switchChannel(channel) {
+        if (channel === this.channelMode) {
+            return;
+        }
+        if (this.isUpdating) {
+            return;
+        }
+        if (!this.hasGit && channel === 'nightly') {
+            const confirmed = await this._confirmChannelSwitch(
+                'update.channelSwitch.nightlyTitle',
+                'update.channelSwitch.nightlyMessage'
+            );
+            if (!confirmed) return;
+        }
+        if (this.hasGit && channel === 'release') {
+            const confirmed = await this._confirmChannelSwitch(
+                'update.channelSwitch.releaseTitle',
+                'update.channelSwitch.releaseMessage'
+            );
+            if (!confirmed) return;
+        }
+
+        try {
+            this.isUpdating = true;
+            this.showUpdateProgress(true);
+            this.updateProgress(10, translate('update.channelSwitch.switching', { channel }));
+
+            const response = await fetch('/api/lm/switch-channel', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ channel })
+            });
+
+            const data = await response.json();
+
+            if (data.success) {
+                this.channelMode = channel;
+                await this.checkForUpdates({ force: true });
+                this.updateModalContent();
+                this.updateChannelUI();
+                this._showSwitchCompleteMessage(data.new_version);
+                this.progressKeepVisible = true;
+            } else {
+                throw new Error(data.error || translate('update.channelSwitch.failed'));
+            }
+        } catch (error) {
+            console.error('Channel switch failed:', error);
+            this.updateProgress(0, translate('update.channelSwitch.failed'));
+        } finally {
+            if (this.progressKeepVisible) {
+                this.isUpdating = false;
+                this.progressKeepVisible = false;
+            } else {
+                setTimeout(() => {
+                    this.showUpdateProgress(false);
+                    this.isUpdating = false;
+                }, 2000);
+            }
+        }
+    }
+
+    updateChannelUI() {
+        const releaseBtn = document.getElementById('channelRelease');
+        const nightlyBtn = document.getElementById('channelNightly');
+
+        if (releaseBtn) {
+            releaseBtn.classList.toggle('active', this.channelMode === 'release');
+        }
+        if (nightlyBtn) {
+            nightlyBtn.classList.toggle('active', this.channelMode === 'nightly');
+        }
+    }
+
+    async _confirmChannelSwitch(titleKey, messageKey) {
+        return new Promise((resolve) => {
+            const title = translate(titleKey);
+            const message = translate(messageKey);
+            const cancelText = translate('common.cancel');
+            const confirmText = translate('common.confirm');
+
+            const overlay = document.createElement('div');
+            overlay.className = 'channel-switch-overlay';
+            overlay.innerHTML = `
+                <div class="channel-switch-dialog">
+                    <h3>${title}</h3>
+                    <p>${message}</p>
+                    <div class="channel-switch-actions">
+                        <button class="secondary-btn channel-switch-cancel">${cancelText}</button>
+                        <button class="primary-btn channel-switch-confirm">${confirmText}</button>
+                    </div>
+                </div>
+            `;
+
+            const dismiss = (result) => {
+                document.removeEventListener('keydown', onKeydown);
+                overlay.remove();
+                resolve(result);
+            };
+
+            const onKeydown = (e) => {
+                if (e.key === 'Escape') {
+                    e.stopPropagation();
+                    e.preventDefault();
+                    dismiss(false);
+                }
+            };
+
+            document.addEventListener('keydown', onKeydown, { capture: true });
+
+            overlay.addEventListener('click', (e) => {
+                if (e.target === overlay) {
+                    dismiss(false);
+                }
+            });
+
+            overlay.querySelector('.channel-switch-cancel').addEventListener('click', () => {
+                dismiss(false);
+            });
+
+            overlay.querySelector('.channel-switch-confirm').addEventListener('click', () => {
+                dismiss(true);
+            });
+
+            document.body.appendChild(overlay);
+        });
     }
 
     setupNotificationCenter() {
@@ -373,7 +493,8 @@ export class UpdateService {
 
         try {
             // Call backend API to check for updates with nightly flag
-            const response = await fetch(`/api/lm/check-updates?nightly=${this.nightlyMode}`);
+            const nightly = this.channelMode === 'nightly';
+            const response = await fetch(`/api/lm/check-updates?nightly=${nightly}`);
             const data = await response.json();
             
             if (data.success) {
@@ -381,17 +502,19 @@ export class UpdateService {
                 this.latestVersion = data.latest_version || "v0.0.0";
                 this.updateInfo = data;
                 this.gitInfo = data.git_info || this.gitInfo;
-                
+                this.hasGit = data.has_git || false;
-                // Explicitly set update availability based on version comparison
+                if (this.channelMode === null) {
-                this.updateAvailable = this.isNewerVersion(this.latestVersion, this.currentVersion);
+                    this.channelMode = this.hasGit ? 'nightly' : 'release';
-                
+                }
-                // Update last check time
+
+                this.updateAvailable = data.update_available;
+
                 this.lastCheckTime = now;
                 setStorageItem('last_update_check', now.toString());
-                
+
-                // Update UI
                 this.updateBadgeVisibility();
                 this.updateModalContent();
+                this.updateChannelUI();
 
                 console.log("Update check complete:", {
                     currentVersion: this.currentVersion,
@@ -482,8 +605,27 @@ export class UpdateService {
         
         if (currentVersionEl) currentVersionEl.textContent = this.currentVersion;
         
+        const newVersionLabel = modal.querySelector('.new-version .label');
+        if (newVersionLabel) {
+            newVersionLabel.textContent = (this.updateInfo?.nightly)
+                ? `${translate('update.latestMain')}:`
+                : `${translate('update.newVersion')}:`;
+        }
+
         if (newVersionEl) {
-            newVersionEl.textContent = this.latestVersion;
+            if (this.updateInfo?.nightly) {
+                const behind = this.updateInfo.behind_by || 0;
+                const hash = this.latestVersion.replace('main-', '');
+                const date = this.updateInfo.commit_date || '';
+                const datePart = date ? ` · ${date}` : '';
+                if (behind > 0) {
+                    newVersionEl.textContent = `${behind} commit${behind !== 1 ? 's' : ''} behind main (${hash}${datePart})`;
+                } else {
+                    newVersionEl.textContent = `Up to date (${hash}${datePart})`;
+                }
+            } else {
+                newVersionEl.textContent = this.latestVersion;
+            }
         }
         
         // Update update button state
@@ -599,8 +741,12 @@ export class UpdateService {
         // Update GitHub link to point to the specific release if available
         const githubLink = modal.querySelector('.update-link');
         if (githubLink && this.latestVersion) {
-            const versionTag = this.latestVersion.replace(/^v/, '');
+            if (this.updateInfo?.nightly) {
-            githubLink.href = `https://github.com/willmiao/ComfyUI-Lora-Manager/releases/tag/v${versionTag}`;
+                githubLink.href = 'https://github.com/willmiao/ComfyUI-Lora-Manager/commits/main';
+            } else {
+                const versionTag = this.latestVersion.replace(/^v/, '');
+                githubLink.href = `https://github.com/willmiao/ComfyUI-Lora-Manager/releases/tag/v${versionTag}`;
+            }
         }
     }
     
@@ -623,7 +769,7 @@ export class UpdateService {
                     'Content-Type': 'application/json'
                 },
                 body: JSON.stringify({
-                    nightly: this.nightlyMode
+                    nightly: this.channelMode === 'nightly'
                 })
             });
             
@@ -698,7 +844,26 @@ export class UpdateService {
             progressText.textContent = text;
         }
     }
-    
+
+    _showSwitchCompleteMessage(version) {
+        this.showUpdateProgress(true);
+        this.updateProgress(100, '');
+        const progressText = document.getElementById('updateProgressText');
+        if (progressText) {
+            progressText.innerHTML = `
+                <div style="text-align: center; color: var(--lora-success);">
+                    <i class="fas fa-check-circle" style="margin-right: 8px;"></i>
+                    ${translate('update.completion.successMessage', { version })}
+                    <br><br>
+                    <div style="opacity: 0.95; color: var(--lora-error); font-size: 1em;">
+                        ${translate('update.completion.restartMessage')}<br>
+                        ${translate('update.completion.reloadMessage')}
+                    </div>
+                </div>
+            `;
+        }
+    }
+
     showUpdateCompleteMessage(newVersion) {
         const modal = document.getElementById('updateModal');
         if (!modal) return;
@@ -771,6 +936,7 @@ export class UpdateService {
 
         // Update the modal content immediately with current data
         this.updateModalContent();
+        this.updateChannelUI();
         this.renderRecentBanners();
 
         // Show the modal with current data
@@ -801,8 +967,8 @@ export class UpdateService {
             
             if (data.success) {
                 this.currentVersionInfo = data.version;
-                
+                this.hasGit = data.has_git || false;
-                // Check if version matches stored version
+
                 this.versionMismatch = !isVersionMatch(this.currentVersionInfo);
                 
                 if (this.versionMismatch) {

templates/components/modals/update_modal.html

@@ -19,6 +19,20 @@
         <div class="notification-panels">
             <div class="notification-panel active" id="updatesPanel" role="tabpanel" aria-labelledby="updatesTab" aria-hidden="false" tabindex="0" data-notification-panel="updates">
                 <div class="update-content">
+
+                    <!-- Channel Selector -->
+                    <div class="update-channels" id="updateChannels">
+                        <div class="channels-label">{{ t('update.channel') }}</div>
+                        <div class="channel-toggle">
+                            <button type="button" class="channel-btn" data-channel="release" id="channelRelease">
+                                <i class="fas fa-tag"></i> {{ t('update.channels.release') }}
+                            </button>
+                            <button type="button" class="channel-btn" data-channel="nightly" id="channelNightly">
+                                <i class="fas fa-moon"></i> {{ t('update.channels.nightly') }}
+                            </button>
+                        </div>
+                    </div>
+
                     <div class="update-info">
                         <div class="version-info">
                             <div class="current-version">

tests/routes/test_update_routes.py

@@ -1,10 +1,33 @@
 import logging
+import os
+import shutil
 from aiohttp import ClientError
+from aiohttp import web
 import pytest
 
 from py.routes import update_routes
 
 
+def _fake_request(body=None, query_params=None):
+    from multidict import MultiDict
+
+    q = MultiDict(query_params or {})
+
+    req = type("Req", (), {
+        "has_body": body is not None,
+        "match_info": {},
+        "rel_url": type("U", (), {"query": q})(),
+        "query": q,
+        "app": {},
+    })()
+
+    async def _json():
+        return body or {}
+
+    req.json = _json
+    return req
+
+
 class OfflineDownloader:
     async def make_request(self, *_, **__):
         return False, "Cannot connect to host"
@@ -53,10 +76,12 @@ async def test_get_nightly_version_network_error_logs_warning(monkeypatch, caplo
     caplog.set_level(logging.WARNING)
     monkeypatch.setattr(update_routes, "get_downloader", lambda: _stub_downloader(RaisingDownloader()))
 
-    version, changelog = await update_routes.UpdateRoutes._get_nightly_version()
+    version, changelog, behind_by, commit_date = await update_routes.UpdateRoutes._get_nightly_version()
 
     assert version == "main"
     assert changelog == []
+    assert behind_by == 0
+    assert commit_date == ""
     assert "Unable to reach GitHub for nightly version" in caplog.text
     assert "Traceback" not in caplog.text
 
@@ -236,3 +261,240 @@ async def test_perform_git_update_stable_preserves_user_dirs(monkeypatch, tmp_pa
     clean_args = clean_calls[0][1]
     for name in update_routes._PRESERVE_DIRS:
         assert name in clean_args, f"{name} missing from git clean excludes (stable)"
+
+def test_init_git_repo_creates_valid_repo(tmp_path, monkeypatch):
+    if not shutil.which("git"):
+        pytest.skip("git executable not found")
+
+    plugin_root = tmp_path / "plugin"
+    plugin_root.mkdir()
+    (plugin_root / ".tracking").write_text("pyproject.toml")
+    (plugin_root / "settings.json").write_text('{"some": "value"}')
+
+    try:
+        success, version = update_routes.UpdateRoutes._init_git_repo(str(plugin_root))
+    except Exception as e:
+        pytest.skip(f"Network unavailable for git fetch: {e}")
+
+    assert success is True
+    assert version.startswith("main-")
+    assert len(version) > len("main-")
+    assert (plugin_root / ".git").is_dir()
+    assert not (plugin_root / ".tracking").exists()
+    assert (plugin_root / "settings.json").exists()
+    assert (plugin_root / "pyproject.toml").exists()
+
+
+@pytest.mark.asyncio
+async def test_switch_channel_invalid_channel_returns_error():
+    req = _fake_request({"channel": "bad_channel"})
+    resp = await update_routes.UpdateRoutes.switch_channel(req)
+
+    data = _raw_body(resp)
+    assert not data["success"]
+    assert "Invalid channel" in data["error"]
+
+
+@pytest.mark.asyncio
+async def test_switch_channel_to_nightly_without_git_inits_repo(monkeypatch, tmp_path):
+    routes_file = tmp_path / "py" / "routes" / "update_routes.py"
+    routes_file.parent.mkdir(parents=True)
+    routes_file.write_text("")
+    monkeypatch.setattr(update_routes, "__file__", str(routes_file))
+    monkeypatch.setattr(update_routes, "ensure_settings_file", lambda logger: str(tmp_path / "settings.json"))
+    monkeypatch.setattr(
+        update_routes.UpdateRoutes,
+        "_init_git_repo",
+        staticmethod(lambda plugin_root: (True, "main-fedcba9")),
+    )
+
+    req = _fake_request({"channel": "nightly"})
+    resp = await update_routes.UpdateRoutes.switch_channel(req)
+    data = _raw_body(resp)
+
+    assert data["success"] is True
+    assert data["channel"] == "nightly"
+    assert data["new_version"] == "main-fedcba9"
+
+
+@pytest.mark.asyncio
+async def test_switch_channel_to_nightly_with_git_calls_git_update(monkeypatch, tmp_path):
+    routes_file = tmp_path / "py" / "routes" / "update_routes.py"
+    routes_file.parent.mkdir(parents=True)
+    routes_file.write_text("")
+    monkeypatch.setattr(update_routes, "__file__", str(routes_file))
+    monkeypatch.setattr(update_routes, "ensure_settings_file", lambda logger: str(tmp_path / "settings.json"))
+
+    (tmp_path / ".git").mkdir()
+
+    async def _fake_git_update(*args, **kwargs):
+        return True, "main-1111111"
+
+    monkeypatch.setattr(
+        update_routes.UpdateRoutes, "_perform_git_update", _fake_git_update
+    )
+
+    req = _fake_request({"channel": "nightly"})
+    resp = await update_routes.UpdateRoutes.switch_channel(req)
+    data = _raw_body(resp)
+
+    assert data["success"] is True
+    assert data["channel"] == "nightly"
+    assert data["new_version"] == "main-1111111"
+
+
+@pytest.mark.asyncio
+async def test_switch_channel_to_release_with_git_downloads_zip(monkeypatch, tmp_path):
+    routes_file = tmp_path / "py" / "routes" / "update_routes.py"
+    routes_file.parent.mkdir(parents=True)
+    routes_file.write_text("")
+    monkeypatch.setattr(update_routes, "__file__", str(routes_file))
+    monkeypatch.setattr(update_routes, "ensure_settings_file", lambda logger: str(tmp_path / "settings.json"))
+
+    (tmp_path / ".git").mkdir()
+
+    async def _fake_zip(*args, **kwargs):
+        return True, "v9.9.9"
+
+    monkeypatch.setattr(
+        update_routes.UpdateRoutes, "_download_and_replace_zip", _fake_zip
+    )
+
+    req = _fake_request({"channel": "release"})
+    resp = await update_routes.UpdateRoutes.switch_channel(req)
+    data = _raw_body(resp)
+
+    assert data["success"] is True
+    assert data["channel"] == "release"
+    assert data["new_version"] == "v9.9.9"
+
+
+@pytest.mark.asyncio
+async def test_switch_channel_to_release_without_git_still_downloads_zip(monkeypatch, tmp_path):
+    routes_file = tmp_path / "py" / "routes" / "update_routes.py"
+    routes_file.parent.mkdir(parents=True)
+    routes_file.write_text("")
+    monkeypatch.setattr(update_routes, "__file__", str(routes_file))
+    monkeypatch.setattr(update_routes, "ensure_settings_file", lambda logger: str(tmp_path / "settings.json"))
+
+    async def _fake_zip(*args, **kwargs):
+        return True, "v2.0.0"
+
+    monkeypatch.setattr(
+        update_routes.UpdateRoutes, "_download_and_replace_zip", _fake_zip
+    )
+
+    req = _fake_request({"channel": "release"})
+    resp = await update_routes.UpdateRoutes.switch_channel(req)
+    data = _raw_body(resp)
+
+    assert data["success"] is True
+    assert data["channel"] == "release"
+    assert data["new_version"] == "v2.0.0"
+
+
+class _NightlyDownloader:
+    """Returns a fake main-branch commit AND a compare response."""
+
+    commit_sha = "7777777"
+    commit_msg = "test: add nightly feature"
+    commit_date = "2026-07-27T12:00:00Z"
+    behind_by = 5
+
+    async def make_request(self, method, url, **kwargs):
+        if "/compare/" in url:
+            return True, {"behind_by": self.behind_by}
+        return True, {
+            "sha": self.commit_sha,
+            "commit": {
+                "message": self.commit_msg,
+                "committer": {"date": self.commit_date},
+            },
+        }
+
+
+@pytest.mark.asyncio
+async def test_get_nightly_version_parses_behind_by(monkeypatch):
+    monkeypatch.setattr(update_routes, "get_downloader", lambda: _stub_downloader(_NightlyDownloader()))
+
+    version, changelog, behind_by, commit_date = await update_routes.UpdateRoutes._get_nightly_version(
+        local_hash="abc1234"
+    )
+
+    assert version == "main-7777777"
+    assert behind_by == 5
+    assert commit_date == "2026-07-27"
+    assert len(changelog) == 1
+    assert changelog[0] == "test: add nightly feature"
+
+
+class _CheckUpdatesDownloader:
+    """Fake downloader returning both a release list and a nightly commit + compare."""
+
+    commit_sha = "8888888"
+    commit_date = "2026-07-28T00:00:00Z"
+
+    async def make_request(self, method, url, **kwargs):
+        if "/releases" in url:
+            return True, [
+                {
+                    "tag_name": "v3.0.0",
+                    "body": "- Feature A\n- Feature B",
+                    "published_at": "2026-07-20T00:00:00Z",
+                }
+            ]
+        if "/compare/" in url:
+            return True, {"behind_by": 3}
+        return True, {
+            "sha": self.commit_sha + "0" * 33,
+            "commit": {
+                "message": "latest commit",
+                "committer": {"date": self.commit_date},
+            },
+        }
+
+
+@pytest.mark.asyncio
+async def test_check_updates_nightly_response_includes_behind_and_date(monkeypatch, tmp_path):
+    monkeypatch.setattr(update_routes, "get_downloader", lambda: _stub_downloader(_CheckUpdatesDownloader()))
+
+    monkeypatch.setattr(
+        update_routes.UpdateRoutes,
+        "_get_local_version",
+        staticmethod(lambda: "v1.0.0"),
+    )
+    monkeypatch.setattr(
+        update_routes.UpdateRoutes,
+        "_get_git_info",
+        staticmethod(lambda: {
+            "commit_hash": "abc1234",
+            "short_hash": "abc1234",
+            "branch": "main",
+            "commit_date": "2026-01-01",
+        }),
+    )
+
+    routes_file = tmp_path / "py" / "routes" / "update_routes.py"
+    routes_file.parent.mkdir(parents=True)
+    routes_file.write_text("")
+    monkeypatch.setattr(update_routes, "__file__", str(routes_file))
+    (tmp_path / ".git").mkdir()
+
+    req = _fake_request(query_params={"nightly": "true"})
+    resp = await update_routes.UpdateRoutes.check_updates(req)
+    data = _raw_body(resp)
+
+    assert data["success"] is True
+    assert data["nightly"] is True
+    assert data["has_git"] is True
+    assert data["behind_by"] == 3
+    assert data["commit_date"] == "2026-07-28"
+    assert data["latest_version"] == "main-8888888"
+    assert isinstance(data["releases"], list)
+    assert len(data["releases"]) == 1
+    assert data["releases"][0]["version"] == "v3.0.0"
+
+
+def _raw_body(response):
+    import json
+    return json.loads(response._body.decode())