fix(githooks): cd to worktree root before running build

When git invokes post-receive, cwd is GIT_DIR (not worktree root).
`git rev-parse --show-toplevel` refuses to run from a bare context,
so the script would silently cd into .git/. Use `--absolute-git-dir`
and its parent to find the worktree reliably.

Also: receive.denyCurrentBranch=false means push does NOT auto-update
the worktree, so the hook must do `git reset --hard HEAD` to sync
the source the build will use.

.githooks/post-receive

@@ -1,15 +1,25 @@
 #!/bin/sh
 # Post-receive hook: push 后自动 build + start
 #
-echo "DEBUG: PWD=$PWD GIT_DIR=$GIT_DIR GIT_WORK_TREE=$GIT_WORK_TREE HOME=$HOME USER=$USER" >&2
+# 重要：git 调钩子时 cwd=GIT_DIR（不是工作树根），所以必须先把 cwd
+#       切到工作树根，下面的所有路径（env-example/、logs/、pnpm）才正确。
 
 # pnpm 环境变量
 export NVM_DIR="$HOME/.nvm"
 [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
 [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion
 
+# 关键：git 调钩子时 cwd=GIT_DIR，且`git rev-parse --show-toplevel`会拒返回。
+# 用 `git rev-parse --absolute-git-dir` 拿到绝对 git-dir 路径，
+# 其父目录就是工作树根。
+GIT_DIR_ABS="$(git rev-parse --absolute-git-dir 2>/dev/null)"
+if [ -n "$GIT_DIR_ABS" ] && [ -d "$GIT_DIR_ABS" ]; then
+    REPO_TOPLEVEL="$(cd "$GIT_DIR_ABS/.." && pwd)"
+else
     REPO_TOPLEVEL="$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")"
+fi
 cd "$REPO_TOPLEVEL" || { echo "FATAL: cannot cd to $REPO_TOPLEVEL" >&2; exit 1; }
+echo "=== REPO_TOPLEVEL=$REPO_TOPLEVEL (GIT_DIR=$GIT_DIR_ABS) ===" >&2
 
 # ============================================================
 # 0. sync_worktree —— 将**工**作**树**同步到**新** push 的 HEAD