💥 feat(agent)!: 添加主机监控代理首版

* 实现周期采集、快照缓存、本地 HTTP API 和主动上报

* 补齐 Linux 和 Windows 主机、网络、资源、进程和 TCP 采集

* 添加服务生命周期管理、配置加载、构建脚本和测试覆盖

BREAKING CHANGE: network.ips 拆分为 network.ipv4s 和 network.ipv6s。

internal/reporter/reporter_test.go

@@ -0,0 +1,138 @@
+package reporter
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"mfd-monitor-agent/internal/status"
+)
+
+// StaticProvider is a test provider with a fixed cached snapshot.
+type StaticProvider struct {
+	Snapshot status.HostStatus
+	OK       bool
+}
+
+// Get returns the configured static snapshot and readiness flag.
+func (p StaticProvider) Get() (status.HostStatus, bool) {
+	return p.Snapshot, p.OK
+}
+
+// TestReportPostsHostStatusJSON verifies reports reuse the HostStatus JSON payload.
+func TestReportPostsHostStatusJSON(t *testing.T) {
+	var got status.HostStatus
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Fatalf("method = %s", r.Method)
+		}
+		if r.Header.Get("Content-Type") != "application/json" {
+			t.Fatalf("content type = %q", r.Header.Get("Content-Type"))
+		}
+		if err := json.NewDecoder(r.Body).Decode(&got); err != nil {
+			t.Fatal(err)
+		}
+		w.WriteHeader(http.StatusAccepted)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, time.Second)
+	err := client.Report(status.HostStatus{Host: status.HostInfo{Hostname: "host-a"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Host.Hostname != "host-a" {
+		t.Fatalf("posted hostname = %q", got.Host.Hostname)
+	}
+}
+
+// TestReportReturnsErrorForHTTPFailure verifies non-2xx responses fail one report.
+func TestReportReturnsErrorForHTTPFailure(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, time.Second)
+	if err := client.Report(status.HostStatus{}); err == nil {
+		t.Fatal("expected error for HTTP 500")
+	}
+}
+
+// TestRunRetriesFailedReportOnce verifies the loop retries one failed report.
+func TestRunRetriesFailedReportOnce(t *testing.T) {
+	var requests atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		if requests.Add(1) == 1 {
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		w.WriteHeader(http.StatusAccepted)
+	}))
+	defer server.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	provider := StaticProvider{Snapshot: status.HostStatus{Host: status.HostInfo{Hostname: "host-a"}}, OK: true}
+	client := NewClient(server.URL, time.Second)
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		runWithRetryDelay(ctx, provider, client, 10*time.Millisecond, time.Millisecond, slog.New(slog.NewTextHandler(io.Discard, nil)))
+	}()
+
+	deadline := time.After(time.Second)
+	for requests.Load() < 2 {
+		select {
+		case <-deadline:
+			t.Fatalf("requests = %d", requests.Load())
+		case <-time.After(time.Millisecond):
+		}
+	}
+	cancel()
+	<-done
+}
+
+// TestRunStopsDuringRetryDelayWhenContextCanceled verifies retry waits honor cancellation.
+func TestRunStopsDuringRetryDelayWhenContextCanceled(t *testing.T) {
+	var requests atomic.Int32
+	firstRequest := make(chan struct{})
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		if requests.Add(1) == 1 {
+			close(firstRequest)
+		}
+		w.WriteHeader(http.StatusInternalServerError)
+	}))
+	defer server.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	provider := StaticProvider{Snapshot: status.HostStatus{}, OK: true}
+	client := NewClient(server.URL, time.Second)
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		runWithRetryDelay(ctx, provider, client, time.Millisecond, time.Hour, slog.New(slog.NewTextHandler(io.Discard, nil)))
+	}()
+
+	select {
+	case <-firstRequest:
+	case <-time.After(time.Second):
+		t.Fatal("initial report did not run")
+	}
+	cancel()
+
+	select {
+	case <-done:
+	case <-time.After(100 * time.Millisecond):
+		t.Fatal("run did not stop during retry delay")
+	}
+	if requests.Load() != 1 {
+		t.Fatalf("requests = %d", requests.Load())
+	}
+}