Add fallback PromptKit profile assets

internal/framework/llm/promptkit_client_test.go

@@ -431,6 +431,84 @@ func TestPromptKitClientCheckpointFingerprintTracksProfileSource(t *testing.T) {
 	}
 }
 
+func TestPromptKitClientUsesFallbackProfilesForExecutionAndInspection(t *testing.T) {
+	assets := newTestPromptKitAssets(t)
+	const profileID = "fallback-profile"
+	if err := assets.RegisterFallbackProfileFS(fstest.MapFS{
+		"profiles/fallback.yaml": {Data: []byte("id: " + profileID + "\nendpoint: http://promptkit.test/v1\nmodel: fallback-model\n")},
+	}, "profiles"); err != nil {
+		t.Fatalf("RegisterFallbackProfileFS() error = %v, want nil", err)
+	}
+	fake := &fakePromptKitLLM{content: `{"ok":true}`}
+	client, err := NewPromptKitClient(PromptKitClientConfig{
+		Assets:        assets,
+		EngineOptions: []promptkit.Option{promptkit.WithLLMClient(fake)},
+	})
+	if err != nil {
+		t.Fatalf("NewPromptKitClient() error = %v, want nil", err)
+	}
+	var out map[string]any
+	response, err := client.CompleteStructured(context.Background(), contracts.StructuredCompletionRequest{
+		PromptID:  "adapter.test",
+		ProfileID: profileID,
+		SessionID: "fallback-profile-test",
+		Inputs: contracts.LLMInputSet{
+			"transcript": contracts.NewLLMInputMaterial("transcript", "application/json", []byte(`{"source":true}`), "", ""),
+		},
+	}, &out)
+	if err != nil {
+		t.Fatalf("CompleteStructured() error = %v, want nil", err)
+	}
+	if response.ProfileID != profileID || response.Model != "fallback-model" {
+		t.Fatalf("completion response = %#v, want fallback profile", response)
+	}
+
+	inspector, err := NewPromptKitProfileInspector(PromptKitProfileInspectorConfig{Assets: assets})
+	if err != nil {
+		t.Fatalf("NewPromptKitProfileInspector() error = %v, want nil", err)
+	}
+	inspection, err := inspector.InspectProfile(context.Background(), profileID)
+	if err != nil {
+		t.Fatalf("InspectProfile() error = %v, want nil", err)
+	}
+	if inspection.ProfileID != profileID || inspection.Model != "fallback-model" {
+		t.Fatalf("profile inspection = %#v, want fallback profile", inspection)
+	}
+}
+
+func TestPromptKitClientCheckpointFingerprintTracksFallbackProfileAssets(t *testing.T) {
+	fingerprintFor := func(content string) CheckpointFingerprint {
+		t.Helper()
+		assets := newTestPromptKitAssets(t)
+		if err := assets.RegisterFallbackProfileFS(fstest.MapFS{
+			"profiles/fallback.yaml": {Data: []byte(content)},
+		}, "profiles"); err != nil {
+			t.Fatal(err)
+		}
+		client, err := NewPromptKitClient(PromptKitClientConfig{Assets: assets})
+		if err != nil {
+			t.Fatal(err)
+		}
+		fingerprints, err := client.LLMCheckpointFingerprints()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(fingerprints) != 1 || fingerprints[0].Name != promptKitProfileFingerprintName {
+			t.Fatalf("checkpoint fingerprints = %#v, want profile source identity", fingerprints)
+		}
+		return fingerprints[0]
+	}
+
+	first := fingerprintFor("id: fallback\nendpoint: http://promptkit.test/v1\nmodel: model-one\n")
+	second := fingerprintFor("id: fallback\nendpoint: http://promptkit.test/v1\nmodel: model-two\n")
+	if first == second {
+		t.Fatalf("checkpoint fingerprints = %#v and %#v, want fallback asset change", first, second)
+	}
+	if strings.Contains(first.Value, "model-one") || strings.Contains(first.Value, "fallback.yaml") {
+		t.Fatalf("checkpoint fingerprint leaked fallback source details: %#v", first)
+	}
+}
+
 func TestPromptKitClientCheckpointFingerprintTracksLocalBackendTarget(t *testing.T) {
 	const (
 		firstEndpoint  = "http://localhost:8000/v1"