feat(02-02): capture, scrub, and strictly diff stateful flows

Resolve named placeholders from a private variable store, mask
dates and ids after shape checks, and keep comparing independent steps.

Co-authored-by: Cursor <cursoragent@cursor.com>

tide/flow_test.go

@@ -0,0 +1,80 @@
+package tide
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+)
+
+func TestFlowMismatchContinuesAndCaptureSkipsRest(t *testing.T) {
+	var hits atomic.Int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		hits.Add(1)
+		w.Header().Set("Content-Type", "application/json")
+		switch r.URL.Path {
+		case "/one":
+			_, _ = w.Write([]byte(`{"data":"no"}`))
+		default:
+			_, _ = w.Write([]byte(`{"data":"ok"}`))
+		}
+	}))
+	t.Cleanup(srv.Close)
+
+	mismatch := Flow{
+		Version: 1,
+		Name:    "mismatch-continue",
+		Steps: []Step{
+			{
+				ID:       "a",
+				Request:  Request{Method: http.MethodGet, Path: "/one"},
+				Response: Response{Status: 200, Headers: jsonCT(), Body: Body(`{"data":"yes"}`)},
+			},
+			{
+				ID:       "b",
+				Request:  Request{Method: http.MethodGet, Path: "/two"},
+				Response: Response{Status: 200, Headers: jsonCT(), Body: Body(`{"data":"ok"}`)},
+			},
+		},
+	}
+	res, err := ReplayFlow(context.Background(), mismatch, ReplayConfig{Target: srv.URL})
+	if err == nil {
+		t.Fatal("mismatch must error")
+	}
+	if hits.Load() != 2 {
+		t.Fatalf("mismatch should continue, hits=%d", hits.Load())
+	}
+	if len(res.Steps) != 2 || res.Steps[1].Skipped || !res.Steps[1].OK {
+		t.Fatalf("step b should run and pass: %+v", res.Steps)
+	}
+
+	hits.Store(0)
+	captureFail := Flow{
+		Version: 1,
+		Name:    "capture-skip",
+		Steps: []Step{
+			{
+				ID:      "a",
+				Request: Request{Method: http.MethodGet, Path: "/two"},
+				Response: Response{Status: 200, Headers: jsonCT(), Body: Body(`{"data":"ok"}`)},
+				Capture: []CaptureRule{{From: "response.json", Path: "$.token", As: "jwt:alice"}},
+			},
+			{
+				ID:       "b",
+				Request:  Request{Method: http.MethodGet, Path: "/two"},
+				Response: Response{Status: 200, Headers: jsonCT(), Body: Body(`{"data":"ok"}`)},
+			},
+		},
+	}
+	res, err = ReplayFlow(context.Background(), captureFail, ReplayConfig{Target: srv.URL})
+	if err == nil {
+		t.Fatal("failed capture must error")
+	}
+	if hits.Load() != 1 {
+		t.Fatalf("capture fail should skip rest, hits=%d", hits.Load())
+	}
+	if len(res.Steps) != 2 || !res.Steps[1].Skipped {
+		t.Fatalf("step b should skip: %+v", res.Steps)
+	}
+}