test(05-03): add failing tests for VerifyAll worker pool

- TestVerifyAll_MultipleFindings: 5 findings via 3-worker pool
- TestVerifyAll_MissingProvider: unknown provider yields StatusUnknown
- TestVerifyAll_ContextCancellation: cancellation closes channel early
- Add providers.NewRegistryFromProviders test helper

pkg/verify/verifier_test.go

@@ -7,6 +7,7 @@ import (
 	"net/http/httptest"
 	"regexp"
 	"strings"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -172,6 +173,89 @@ func TestVerify_HTTPRejected(t *testing.T) {
 	assert.True(t, strings.Contains(strings.ToLower(res.Error), "https"), "error should mention HTTPS: %q", res.Error)
 }
 
+func TestVerifyAll_MultipleFindings(t *testing.T) {
+	var hits int32
+	srv := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&hits, 1)
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer srv.Close()
+
+	v := newTestVerifier(t, srv, 5*time.Second)
+	prov := testProvider(providers.VerifySpec{URL: srv.URL})
+	reg := providers.NewRegistryFromProviders([]providers.Provider{prov})
+
+	var findings []engine.Finding
+	for i := 0; i < 5; i++ {
+		findings = append(findings, testFinding("sk-test-keyvalue"))
+	}
+
+	out := v.VerifyAll(context.Background(), findings, reg, 3)
+	var got int
+	for res := range out {
+		assert.Equal(t, StatusLive, res.Status)
+		got++
+	}
+	assert.Equal(t, 5, got)
+	assert.Equal(t, int32(5), atomic.LoadInt32(&hits))
+}
+
+func TestVerifyAll_MissingProvider(t *testing.T) {
+	v := NewHTTPVerifier(5 * time.Second)
+	reg := providers.NewRegistryFromProviders(nil)
+
+	f := engine.Finding{ProviderName: "nonexistent", KeyValue: "x", KeyMasked: "****"}
+	out := v.VerifyAll(context.Background(), []engine.Finding{f}, reg, 2)
+
+	res, ok := <-out
+	require.True(t, ok, "expected a result before close")
+	assert.Equal(t, StatusUnknown, res.Status)
+	assert.Contains(t, strings.ToLower(res.Error), "not found")
+
+	_, more := <-out
+	assert.False(t, more, "channel should close after single result")
+}
+
+func TestVerifyAll_ContextCancellation(t *testing.T) {
+	srv := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		select {
+		case <-time.After(100 * time.Millisecond):
+		case <-r.Context().Done():
+		}
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer srv.Close()
+
+	v := newTestVerifier(t, srv, 5*time.Second)
+	prov := testProvider(providers.VerifySpec{URL: srv.URL})
+	reg := providers.NewRegistryFromProviders([]providers.Provider{prov})
+
+	findings := make([]engine.Finding, 100)
+	for i := range findings {
+		findings[i] = testFinding("sk-test-keyvalue")
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	out := v.VerifyAll(ctx, findings, reg, 4)
+	time.AfterFunc(50*time.Millisecond, cancel)
+
+	done := make(chan int, 1)
+	go func() {
+		n := 0
+		for range out {
+			n++
+		}
+		done <- n
+	}()
+
+	select {
+	case n := <-done:
+		assert.Less(t, n, 100, "expected partial results due to cancellation, got %d", n)
+	case <-time.After(3 * time.Second):
+		t.Fatal("channel did not close within 3s after cancellation")
+	}
+}
+
 func TestVerify_Timeout(t *testing.T) {
 	srv := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		time.Sleep(300 * time.Millisecond)