Fix git clone failure in restricted Docker environments

[Copilot]

Repository subscriptions fail on Synology NAS and similar Docker environments with error: unable to get random bytes for temporary file: Function not implemented. Git's temporary file creation attempts to use getrandom() syscall or /dev/random, which are blocked in containers with restricted syscalls.

Changes

• Set TMPDIR=/tmp before git clone operations in git_clone_scripts()
• Preserve and restore original TMPDIR value to avoid side effects

# Before
git clone -q --depth=1 $part_cmd $url $dir

# After
local original_tmpdir="${TMPDIR:-}"
export TMPDIR=/tmp
git clone -q --depth=1 $part_cmd $url $dir
exit_status=$?
if [[ -n "$original_tmpdir" ]]; then
  export TMPDIR="$original_tmpdir"
else
  unset TMPDIR
fi

This forces git to use standard temp directory APIs instead of system random sources.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>订阅功能失效</issue_title>
<issue_description>### Qinglong version

v2.20.1

Steps to reproduce

添加github仓库订阅
运行订阅

What is expected?

正确拉取仓库文件

What is actually happening?

开始执行... 2025-12-31 18:00:48

开始拉取仓库 Cat-zaizai_ZaiZaiCat-Checkin_main 到 /ql/data/repo/Cat-zaizai_ZaiZaiCat-Checkin_main

error: unable to get random bytes for temporary file: Function not implemented
error: unable to get random bytes for temporary file: Function not implemented
fatal: Unable to create temporary file '/ql/data/repo/Cat-zaizai_ZaiZaiCat-Checkin_main/.git/objects/pack/tmp_pack_XXXXXX': Function not implemented

fatal: fetch-pack: invalid index-pack output

拉取 Cat-zaizai_ZaiZaiCat-Checkin_main 失败，请检查日志...

执行结束... 2025-12-31 18:00:52 耗时 4 秒　　　　　

System Info

群晖，docker部署，从前面的版本更新上来的（重新pull镜像然后用portainer重新部署），未改部署参数

Any additional comments?

试了仅有的2个仓库，都是同样的问题，其中一个仓库属于是以前加入的、能订阅的，现在不能更新了

https://github.com/Cat-zaizai/ZaiZaiCat-Checkin.git
https://github.com/aefa6/QinglongScript.git

询问过gemini，根据gemini的建议给容器添加--privileged=true也没有解决问题</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes 订阅功能失效 #2896

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Project	Deployment	Review	Updated (UTC)
qinglong	Ready	Preview, Comment	Jan 3, 2026 6:59am
qinglong-back	Ready	Preview, Comment	Jan 3, 2026 6:59am