feat(deploy): 画布 Agent - 独立 yingce-agent 容器并修复运行中断

生产会话不再因 stdout 管道提前关闭被误判失败。设置 YINGCE_AGENT_URL 后只走独立容器，失败不回退到内嵌进程。

backend/internal/agent/yingceagent/client.go

@@ -0,0 +1,69 @@
+package yingceagent
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+
+	agentruntime "infinite-canvas/backend/internal/agent/runtime"
+)
+
+// Run executes one Agent session on the independent yingce-agent service.
+// The Go process keeps the bridge, billing, and tool execution. A configured
+// remote endpoint never falls back to an embedded Node process: doing so can
+// run the same step twice.
+func Run(ctx context.Context, endpoint, serviceToken, bridgeHost string, request agentruntime.ProcessRequest, bridge agentruntime.Bridge) error {
+	endpoint = strings.TrimRight(strings.TrimSpace(endpoint), "/")
+	serviceToken = strings.TrimSpace(serviceToken)
+	if endpoint == "" {
+		return fmt.Errorf("YINGCE_AGENT_URL is empty")
+	}
+	if len(serviceToken) < 32 {
+		return fmt.Errorf("YINGCE_AGENT_TOKEN must contain at least 32 characters")
+	}
+	server, err := agentruntime.StartBridge("0.0.0.0:0", bridgeHost, bridge)
+	if err != nil {
+		return err
+	}
+	defer server.Close()
+	request.BridgeURL = server.URL
+	request.BridgeToken = server.Token
+	payload, err := json.Marshal(request)
+	if err != nil {
+		return fmt.Errorf("encode remote Agent request: %w", err)
+	}
+	httpRequest, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint+"/v1/runs", bytes.NewReader(payload))
+	if err != nil {
+		return fmt.Errorf("create remote Agent request: %w", err)
+	}
+	httpRequest.Header.Set("Authorization", "Bearer "+serviceToken)
+	httpRequest.Header.Set("Content-Type", "application/json")
+	response, err := remoteClient.Do(httpRequest)
+	if err != nil {
+		return fmt.Errorf("call yingce-agent: %w", err)
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusOK {
+		detail, _ := io.ReadAll(io.LimitReader(response.Body, 4096))
+		return fmt.Errorf("yingce-agent returned HTTP %d: %s", response.StatusCode, strings.TrimSpace(string(detail)))
+	}
+	return agentruntime.ReadOutput(response.Body)
+}
+
+var remoteClient = &http.Client{
+	Transport: &http.Transport{
+		Proxy: http.ProxyFromEnvironment,
+		DialContext: (&net.Dialer{
+			Timeout:   10 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext,
+		ForceAttemptHTTP2: true,
+		IdleConnTimeout:   90 * time.Second,
+	},
+}

backend/internal/agent/yingceagent/client_test.go

@@ -0,0 +1,119 @@
+package yingceagent
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+	"time"
+
+	agentruntime "infinite-canvas/backend/internal/agent/runtime"
+)
+
+func TestRemoteRunCallsBridgeAndRejectsBadToken(t *testing.T) {
+	if _, err := exec.LookPath("node"); err != nil {
+		t.Skip("node is not installed")
+	}
+	_, source, _, ok := runtime.Caller(0)
+	if !ok {
+		t.Fatal("locate test file")
+	}
+	serverPath := filepath.Clean(filepath.Join(filepath.Dir(source), "../../../../yingce-agent/server.mjs"))
+	runtimePath := filepath.Join(t.TempDir(), "agent-runtime.mjs")
+	script := `
+let raw = "";
+for await (const chunk of process.stdin) raw += chunk;
+const request = JSON.parse(raw);
+const response = await fetch(new URL("/tool", request.bridgeURL), {
+  method: "POST",
+  headers: { "content-type": "application/json", authorization: "Bearer " + request.bridgeToken },
+  body: JSON.stringify({ name: "lookup" }),
+});
+if (!response.ok) {
+  process.stdout.write(JSON.stringify({ event: "runtime_error", message: "bridge " + response.status }) + "\n");
+  process.exitCode = 1;
+} else {
+  process.stdout.write(JSON.stringify({ event: "settled" }) + "\n");
+}
+`
+	if err := os.WriteFile(runtimePath, []byte(script), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	token := strings.Repeat("ab", 16)
+	cmd := exec.Command("node", serverPath)
+	cmd.Env = append(os.Environ(),
+		"YINGCE_AGENT_TOKEN="+token,
+		"YINGCE_AGENT_RUNTIME="+runtimePath,
+		"PORT=0",
+		"MAX_CONCURRENT_SESSIONS=2",
+	)
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cmd.Stderr = os.Stderr
+	if err := cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		_ = cmd.Process.Kill()
+		_, _ = cmd.Process.Wait()
+	})
+	reader := bufio.NewReader(stdout)
+	line, err := reader.ReadString('\n')
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(line, "YINGCE_AGENT_READY ") {
+		t.Fatalf("server did not report its port: %q", line)
+	}
+	endpoint := "http://127.0.0.1:" + strings.TrimSpace(strings.TrimPrefix(line, "YINGCE_AGENT_READY "))
+
+	health, err := http.Get(endpoint + "/healthz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer health.Body.Close()
+	if health.StatusCode != http.StatusOK {
+		t.Fatalf("health status %d", health.StatusCode)
+	}
+
+	unauthorized, err := http.Post(endpoint+"/v1/runs", "application/json", strings.NewReader(`{}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer unauthorized.Body.Close()
+	if unauthorized.StatusCode != http.StatusUnauthorized {
+		t.Fatalf("missing token status %d", unauthorized.StatusCode)
+	}
+
+	called := false
+	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
+	defer cancel()
+	err = Run(ctx, endpoint, token, "127.0.0.1", agentruntime.ProcessRequest{
+		Model: map[string]any{"id": "m"},
+	}, agentruntime.Bridge{
+		Model: func(context.Context, map[string]json.RawMessage) (any, error) {
+			return map[string]any{"ok": true}, nil
+		},
+		Tool: func(context.Context, map[string]json.RawMessage) (any, error) {
+			called = true
+			return map[string]any{"content": "ok"}, nil
+		},
+		Event: func(context.Context, map[string]json.RawMessage) (any, error) {
+			return map[string]any{"ok": true}, nil
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !called {
+		t.Fatal("remote runtime did not call the Go tool bridge")
+	}
+}