refactor: stabilize runtime and unify config

pkg/tools/runtime_snapshot_test.go

@@ -0,0 +1,42 @@
+package tools
+
+import (
+	"context"
+	"testing"
+	"time"
+)
+
+func TestSubagentManagerRuntimeSnapshot(t *testing.T) {
+	workspace := t.TempDir()
+	manager := NewSubagentManager(nil, workspace, nil)
+	manager.SetRunFunc(func(ctx context.Context, task *SubagentTask) (string, error) {
+		return "snapshot-result", nil
+	})
+	task, err := manager.SpawnTask(context.Background(), SubagentSpawnOptions{
+		Task:          "implement snapshot support",
+		AgentID:       "coder",
+		OriginChannel: "cli",
+		OriginChatID:  "direct",
+	})
+	if err != nil {
+		t.Fatalf("spawn task failed: %v", err)
+	}
+	if _, _, err := manager.WaitTask(context.Background(), task.ID); err != nil {
+		t.Fatalf("wait task failed: %v", err)
+	}
+	time.Sleep(10 * time.Millisecond)
+	snapshot := manager.RuntimeSnapshot(20)
+	if len(snapshot.Tasks) == 0 || len(snapshot.Runs) == 0 {
+		t.Fatalf("expected runtime snapshot to include task and run records: %+v", snapshot)
+	}
+	if len(snapshot.Threads) == 0 || len(snapshot.Artifacts) == 0 {
+		t.Fatalf("expected runtime snapshot to include thread and artifact records: %+v", snapshot)
+	}
+	msgArtifact := snapshot.Artifacts[0]
+	if msgArtifact.SourceType != "agent_message" {
+		t.Fatalf("expected agent message artifact source type, got %+v", msgArtifact)
+	}
+	if msgArtifact.FromAgent == "" || msgArtifact.ToAgent == "" || msgArtifact.Name == "" {
+		t.Fatalf("expected runtime snapshot artifact to preserve message metadata, got %+v", msgArtifact)
+	}
+}