🧪 test(algos): 新增签名算法 golden 测试

固定输入与时间戳断言 Gorgon/8404/Ladon 输出及 Argus 哈希层。
Go 1.25 起 rand.Seed 默认 no-op，用 //go:debug randseednop=0 钉住随机序列；
Argus 因 protobuf 按 map 迭代序编码无法全量 golden，仅测其确定性哈希。

internal/algos/golden_test.go

@@ -0,0 +1,79 @@
+//go:debug randseednop=0
+
+package algos
+
+import (
+	"encoding/hex"
+	"math/rand"
+	"testing"
+)
+
+// 固定输入 + 固定时间戳的 golden 测试：签名算法被改坏时在此最先失败。
+// 基准值取自当前实现；有意修改算法后用相同输入重新生成并更新期望值。
+// 8404 内嵌随机数且走全局 math/rand，Go 1.25 起 rand.Seed 默认是 no-op，
+// 故用 //go:debug randseednop=0 恢复其钉死随机序列的旧语义。
+// x-argus 的 protobuf 编码按 map 迭代顺序输出（protobuf.go:385），天然
+// 不确定，无法全量 golden，只测其内部的确定性哈希层。
+
+const (
+	goldenParams = "aid=1967&app_name=fanqie_novel&device_id=1234567890123456&version_name=5.9.5"
+	goldenStub   = "d41d8cd98f00b204e9800998ecf8427e"
+	goldenCookie = "install_id=728944090949322; device_id=1234567890123456"
+	goldenSecDev = "1234567890123456"
+	goldenAID    = 1967
+	goldenLcID   = 1611921764
+)
+
+// var：Sign2 需要 *int64，不能对常量取址
+var goldenTS = int64(1700000000)
+
+func goldenArgs() (string, string, string, string, int, int, string, int, int, *int64) {
+	return goldenParams, goldenStub, goldenSecDev, goldenCookie,
+		goldenAID, goldenLcID, "v04.06.01-ml-android", 135004672, 0, &goldenTS
+}
+
+func assertGolden(t *testing.T, name string, got map[string]string, want map[string]string) {
+	t.Helper()
+	for k, v := range want {
+		if got[k] != v {
+			t.Errorf("%s %s = %q, want %q", name, k, got[k], v)
+		}
+	}
+}
+
+func TestGorgonSign2Golden(t *testing.T) {
+	GlobalAlgorithmSwitcher.SwitchAlgorithm("gorgon")
+	assertGolden(t, "gorgon", Sign2(goldenArgs()), map[string]string{
+		"x-gorgon":        "0404b0d30000bbd9e75fe1edb046d324b7853694a6177ca72d0a",
+		"x-khronos":       "1700000000",
+		"x-ss-req-ticket": "1700000000000",
+	})
+}
+
+func TestAlgo8404Sign2Golden(t *testing.T) {
+	rand.Seed(1)
+	GlobalAlgorithmSwitcher.SwitchAlgorithm("8404")
+	defer GlobalAlgorithmSwitcher.SwitchAlgorithm("gorgon")
+	assertGolden(t, "8404", Sign2(goldenArgs()), map[string]string{
+		"X-Gorgon":        "8404210f00008eec413318e9f810571e96fca6fb4a0f497e78e5",
+		"X-Khronos":       "1700000000",
+		"X-SS-REQ-Ticket": "1700000000000",
+	})
+}
+
+func TestLadonGolden(t *testing.T) {
+	// 固定 randomBytes，绕开 crypto/rand
+	got := LadonEncrypt(goldenTS, goldenLcID, goldenAID, []byte{0xde, 0xad, 0xbe, 0xef})
+	if want := "3q2+7/6PK4T/ZqM1zu2AIWFdXW2D9gdHrXRfOb02lxi6GnYm"; got != want {
+		t.Errorf("ladon = %q, want %q", got, want)
+	}
+}
+
+func TestArgusHashGolden(t *testing.T) {
+	if got := hex.EncodeToString(GetBodyHash(goldenStub)); got != "9c840df1aec0" {
+		t.Errorf("bodyHash = %s, want 9c840df1aec0", got)
+	}
+	if got := hex.EncodeToString(GetQueryHash(goldenParams)); got != "58bc068af10b" {
+		t.Errorf("queryHash = %s, want 58bc068af10b", got)
+	}
+}