docs(gateway): gateway 剩余文件注释改中文（逐行 1:1，代码零字节改动）

主人 2026-10-03 拍板「注释一律中文」；gateway 至此整包注释中文化完成（本会话共 3 批：
已推库 16 个文件 + 本批剩余文件）。
校验：机械校验（非注释改动行）= 空；剥注释后代码文本逐行比对全等（不一致文件数 0）；
全树 go test ./... 58 包 ok / 0 FAIL；交叉编译绿。

internal/services/gateway/observability_metrics_test.go

@@ -12,17 +12,17 @@ import (
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/auth"
 )
 
-// These tests pin the contract that broke in production (2026-10-03 21:00:28):
-// MetricsCollector.Snapshot must hand back DETACHED counter maps, because the
-// admin handler JSON-encodes the snapshot after the collector's lock is released.
-// Returning the collector's own maps let a concurrent Record write a map while the
-// encoder iterated it → unrecoverable
-// "fatal error: concurrent map iteration and map write" → the whole backend died,
-// and with it every admin page (the reported「全链路流程功能无效」).
+// 这些测试钉住生产中坏掉的那个契约（2026-10-03 21:00:28）：
+// MetricsCollector.Snapshot 必须交回脱离的计数器 map，因为
+// 管理 handler 在收集器锁释放后对快照做 JSON 编码。
+// 返回收集器自己的 map 会让并发的 Record 在编码器遍历它时
+// 写该 map → 不可恢复的
+// "fatal error: concurrent map iteration and map write" → 整个后端死亡，
+// 随之所有管理页面也死（上报的「全链路流程功能无效」）。
 
-// TestMetricsSnapshotDetachesMaps is the deterministic regression: a value read out
-// of a snapshot must not change when the collector is counted afterwards, and
-// writing into a snapshot must not reach the collector.
+// TestMetricsSnapshotDetachesMaps 是确定性的回归：从快照读出的
+// 值不得在之后对收集器计数时改变，且写入
+// 快照不得触达收集器。
 func TestMetricsSnapshotDetachesMaps(t *testing.T) {
 	t.Parallel()
 	m := newMetricsCollector()
@@ -36,7 +36,7 @@ func TestMetricsSnapshotDetachesMaps(t *testing.T) {
 		t.Fatalf("PerMethod[GET] = %d, want 1", got)
 	}
 
-	// A count recorded after the snapshot must not appear in the older snapshot.
+	// 快照之后记录的计数不得出现在较旧的快照中。
 	m.Record(http.MethodPost, "/api/v1/b", http.StatusTeapot, 1)
 	if _, ok := snap.PerPath["/api/v1/b"]; ok {
 		t.Fatalf("snapshot shares the collector's perPath map: later path leaked into it (%v)", snap.PerPath)
@@ -52,8 +52,8 @@ func TestMetricsSnapshotDetachesMaps(t *testing.T) {
 	assertCollectorNotMutatedBySnapshot(t, m)
 }
 
-// assertSnapshotWriteIsolation writes into the snapshot's maps and checks the
-// collector is untouched afterwards.
+// assertSnapshotWriteIsolation 写入快照的 map 并检查
+// 之后收集器未被触碰。
 func assertSnapshotWriteIsolation(t *testing.T, m *MetricsCollector, snap AdminMetrics) {
 	t.Helper()
 	snap.PerPath["/api/v1/evil"] = 999
@@ -78,8 +78,8 @@ func assertSnapshotWriteIsolation(t *testing.T, m *MetricsCollector, snap AdminM
 	}
 }
 
-// assertCollectorNotMutatedBySnapshot re-reads a counter the collector recorded
-// before the isolation writes to prove no counter value was disturbed.
+// assertCollectorNotMutatedBySnapshot 重新读取收集器在隔离写入之前
+// 记录的一个计数器，以证明没有任何计数值被扰动。
 func assertCollectorNotMutatedBySnapshot(t *testing.T, m *MetricsCollector) {
 	t.Helper()
 	final := m.Snapshot(time.Now())
@@ -91,11 +91,11 @@ func assertCollectorNotMutatedBySnapshot(t *testing.T, m *MetricsCollector) {
 	}
 }
 
-// TestMetricsSnapshotEncodedConcurrently runs the exact interleaving that crashed
-// production: one goroutine counts requests (the logging middleware does this on
-// every request) while another encodes snapshots (the admin handler does this
-// outside the lock). Under -race a shared live map is reported as a data race; on
-// an unpatched build it can also abort the process outright.
+// TestMetricsSnapshotEncodedConcurrently 运行让生产崩溃的那个确切
+// 交错：一个 goroutine 计请求（logging 中间件对每个请求都
+// 这么做），另一个编码快照（管理 handler 在锁外
+// 这么做）。在 -race 下共享活 map 会被报告为数据竞争；在
+// 未打补丁的构建上它还可能直接把进程搞崩。
 func TestMetricsSnapshotEncodedConcurrently(t *testing.T) {
 	t.Parallel()
 	m := newMetricsCollector()
@@ -127,18 +127,18 @@ func TestMetricsSnapshotEncodedConcurrently(t *testing.T) {
 	wg.Wait()
 }
 
-// TestAdminMetricsEndpointConcurrentPoll drives the real HTTP path — the admin
-// panel polls every module in parallel, so one request can be encoding the metrics
-// JSON while another request's logging middleware records into the collector. This
-// is the production crash reproduced end-to-end through the middleware + handler.
+// TestAdminMetricsEndpointConcurrentPoll 驱动真实 HTTP 路径 —— 管理
+// 面板并行轮询每个模块，因此一个请求可能在编码指标
+// JSON，而另一个请求的 logging 中间件正在往收集器里记录。这
+// 是生产崩溃经中间件 + handler 端到端复现。
 func TestAdminMetricsEndpointConcurrentPoll(t *testing.T) {
 	env := newEnv(t, nil, false)
 	tok := env.token(t, auth.RoleOwner)
 	metricsURL := env.ts.URL + "/api/v1/admin/observability/metrics"
 	healthURL := env.ts.URL + "/api/v1/health"
 
-	// Both jobs run concurrently: the panel's metrics reads race the load requests
-	// that keep recording into the collector.
+	// 两个任务并发运行：面板的指标读与持续往收集器
+	// 记录的负载请求相互竞争。
 	for _, err := range runConcurrent(
 		func() error { return driveRequests(healthURL, "", 4, 25) },
 		func() error { return driveRequests(metricsURL, tok, 6, 25) },
@@ -169,7 +169,7 @@ func TestAdminMetricsEndpointConcurrentPoll(t *testing.T) {
 	}
 }
 
-// runConcurrent runs every job in its own goroutine and returns the non-nil errors.
+// runConcurrent 在各自 goroutine 中运行每个任务并返回非 nil 错误。
 func runConcurrent(jobs ...func() error) []error {
 	var wg sync.WaitGroup
 	errs := make([]error, len(jobs))
@@ -184,8 +184,8 @@ func runConcurrent(jobs ...func() error) []error {
 	return errs
 }
 
-// driveRequests issues n GETs of url, workers of them in parallel, using token as
-// a bearer credential when non-empty. It returns the first failure (status or I/O).
+// driveRequests 对 url 发起 n 次 GET，其中 workers 个并行，token 非空
+// 时作为 bearer 凭据。它返回首个失败（状态或 I/O）。
 func driveRequests(url, token string, workers, n int) error {
 	var wg sync.WaitGroup
 	fail := make(chan error, workers)