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/security/ipinfo/ipinfo_test.go

@@ -0,0 +1,27 @@
+package ipinfo
+
+import "testing"
+
+// TestLookupInvalidIP 非法输入必须折叠为展示标签且不 panic，proxied 恒为 false。
+func TestLookupInvalidIP(t *testing.T) {
+	for _, in := range []string{"", "not-an-ip", "999.1.1.1", "  "} {
+		label, proxied := Lookup(in)
+		if proxied {
+			t.Errorf("Lookup(%q) proxied = true, want false", in)
+		}
+		if label == "" {
+			t.Errorf("Lookup(%q) label is empty, want a fallback label", in)
+		}
+	}
+}
+
+// TestLookupReturnsLabel 合法 IP 应返回非空标签且不 panic（不锁定具体归属，
+// 避免上游签名快照更新导致测试抖动）。
+func TestLookupReturnsLabel(t *testing.T) {
+	for _, in := range []string{"1.1.1.1", "8.8.8.8", "2606:4700:4700::1111"} {
+		label, _ := Lookup(in)
+		if label == "" {
+			t.Errorf("Lookup(%q) label is empty", in)
+		}
+	}
+}