chore: baseline snapshot before moderation-strictness feature

Repo .git was damaged (refs/ missing, index truncated, object store near-empty).
Repaired via git init (rebuilt refs), stale index preserved as .git/index.corrupt-20260910.bak,
then full worktree committed as a rollback baseline.

internal/shared/goutil.go

@@ -0,0 +1,20 @@
+package shared
+
+import (
+	"github.com/sirupsen/logrus"
+)
+
+// SafeGo 在独立 goroutine 中执行 fn 并捕获 panic，防止任一 goroutine
+// panic 未恢复导致整个进程崩溃（Go 默认行为：未恢复的 panic 终止进程）。
+//
+// 用法：shared.SafeGo(func() { ... })
+func SafeGo(fn func()) {
+	go func() {
+		defer func() {
+			if r := recover(); r != nil {
+				logrus.WithField("panic", r).Error("goroutine panic recovered")
+			}
+		}()
+		fn()
+	}()
+}