fix(cli): force sync remote tags during updates

docs/cli.md

@@ -376,6 +376,7 @@ moviepilot update all --skip-resources
 说明：
 
 - `update backend` 会更新 Git 仓库并重新安装后端依赖，包括 `moviepilot-rust` 加速扩展
+- 在线更新后端时会强制同步 `origin` 的全部标签，覆盖同名本地标签，以支持 Release 重建；仅存在于本地的标签会保留。分支仍仅允许快进更新，离线更新不同步标签
 - 后端更新前如果检测到已跟踪源码改动，CLI 会列出部分文件并询问是否清空；确认后执行清理并继续更新，拒绝或非交互模式会取消更新
 - `MOVIEPILOT_UPDATE_DEV=true` 时，`moviepilot update` 默认使用 DEV 模式；`--dev` / `--no-dev` 可临时覆盖，省略目标时更新全部组件。进程环境变量优先于配置目录中的 `app.env`
 - DEV 模式后端跟踪当前开发分支，处于 Release 的 detached HEAD 时回到 `v3`；前端下载最新 Release 的 `dist.zip`。显式 `--ref` / `--frontend-version` 优先于默认选择

moviepilot

@@ -210,6 +210,7 @@ Options:
 
 说明:
   - 更新后端依赖时会同步更新 moviepilot-rust PyPI 依赖
+  - 在线更新后端时会以 origin 强制覆盖同名本地标签；分支仍仅允许快进更新
   - 后端更新前如果检测到已跟踪源码改动，CLI 会询问是否清空本地改动；确认后才会继续更新，拒绝或非交互模式会取消更新
   - 可在前端“高级设置 - 实验室”中关闭或重新开启 Rust 加速
 EOF

scripts/local_setup.py

@@ -3802,6 +3802,7 @@ def uninstall_local(
 
 
 def _git_output(*args: str) -> str:
+    """读取当前源码仓库的 Git 命令输出。"""
     return capture(["git", *args], cwd=ROOT)
 
 
@@ -3839,14 +3840,16 @@ def _ensure_git_clean() -> None:
 
 
 def _update_backend_ref(ref: str, *, fetch: bool = True) -> str:
-    """同步后端 Git 引用；分支快进到远端，离线标签不访问网络。"""
+    """同步后端 Git 引用；在线强制同步标签、分支仅快进，离线不访问网络。"""
     if not (ROOT / ".git").exists():
         raise RuntimeError("当前目录不是 Git 仓库，无法更新后端代码。")
 
     _ensure_git_clean()
     if fetch:
         print_step("获取远端更新")
-        run(["git", "fetch", "--tags", "origin"], cwd=ROOT)
+        run(["git", "fetch", "--no-tags", "origin"], cwd=ROOT)
+        # Release 重建可能移动同名标签；强制覆盖仅用于标签引用。
+        run(["git", "fetch", "--no-tags", "origin", "+refs/tags/*:refs/tags/*"], cwd=ROOT)
     else:
         # Release 下载阶段已获取并验证标签，重启安装不得再次依赖网络。
         run(

tests/test_local_setup_update.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import importlib.util
+import subprocess
 import uuid
 from pathlib import Path
 
@@ -88,3 +89,70 @@ def test_dirty_update_stops_without_an_interactive_input(monkeypatch):
         module._ensure_git_clean()
 
     assert commands == []
+
+
+@pytest.fixture
+def moved_tag_repository(tmp_path):
+    """用临时本地仓库模拟远端重建同名标签，不访问外部网络。"""
+    remote = tmp_path / "remote"
+    checkout = tmp_path / "checkout"
+    remote.mkdir()
+
+    def git(path, *args):
+        """隔离 Git 身份和签名配置，执行测试仓库操作。"""
+        return subprocess.check_output(
+            ["git", "-c", "user.name=CLI Test", "-c", "user.email=cli@example.test",
+             "-c", "commit.gpgsign=false", "-c", "tag.gpgsign=false", "-C", str(path), *args],
+            text=True,
+        ).strip()
+
+    git(remote, "init", "-b", "v3")
+    git(remote, "commit", "--allow-empty", "-m", "initial")
+    git(remote, "tag", "v3.1.0")
+    old_sha = git(remote, "rev-parse", "HEAD")
+    git(tmp_path, "clone", str(remote), str(checkout))
+    git(checkout, "tag", "local-only")
+    git(remote, "commit", "--allow-empty", "-m", "rebuild")
+    git(remote, "tag", "--force", "v3.1.0")
+    return checkout, git, old_sha, git(remote, "rev-parse", "HEAD")
+
+
+@pytest.mark.parametrize("ref", ["latest", "v3", "v3.1.0"])
+def test_update_overwrites_moved_remote_tag(monkeypatch, moved_tag_repository, ref):
+    """同名标签随远端更新，同时保留远端没有的本地标签。"""
+    checkout, git, old_sha, new_sha = moved_tag_repository
+    module = load_local_setup_module()
+    monkeypatch.setattr(module, "ROOT", checkout)
+
+    assert module._update_backend_ref(ref) == ("v3" if ref == "latest" else ref)
+
+    assert git(checkout, "rev-parse", "v3.1.0") == new_sha
+    assert git(checkout, "rev-parse", "HEAD") == new_sha
+    assert git(checkout, "rev-parse", "local-only") == old_sha
+
+
+def test_update_moved_tag_does_not_reset_diverged_branch(monkeypatch, moved_tag_repository):
+    """强制同步标签不得覆盖分叉分支上的本地提交。"""
+    checkout, git, _, new_sha = moved_tag_repository
+    git(checkout, "commit", "--allow-empty", "-m", "local work")
+    local_sha = git(checkout, "rev-parse", "HEAD")
+    module = load_local_setup_module()
+    monkeypatch.setattr(module, "ROOT", checkout)
+
+    with pytest.raises(subprocess.CalledProcessError):
+        module._update_backend_ref("latest")
+
+    assert git(checkout, "rev-parse", "HEAD") == local_sha
+    assert git(checkout, "rev-parse", "v3.1.0") == new_sha
+
+
+def test_offline_update_preserves_local_tag(monkeypatch, moved_tag_repository):
+    """离线更新只使用已验证的本地标签，即使远端已更换标签。"""
+    checkout, git, old_sha, _ = moved_tag_repository
+    git(checkout, "remote", "remove", "origin")
+    module = load_local_setup_module()
+    monkeypatch.setattr(module, "ROOT", checkout)
+
+    assert module._update_backend_ref("v3.1.0", fetch=False) == "v3.1.0"
+
+    assert git(checkout, "rev-parse", "HEAD") == old_sha