Add fallback PromptKit profile assets

internal/framework/llm/asset_registry_test.go

@@ -2,6 +2,7 @@ package llm
 
 import (
 	"context"
+	"io/fs"
 	"strings"
 	"testing"
 	"testing/fstest"
@@ -98,6 +99,89 @@ func TestAssetRegistryRejectsDuplicateAssetPaths(t *testing.T) {
 	}
 }
 
+func TestAssetRegistryCombinesFallbackProfileSources(t *testing.T) {
+	registry := NewAssetRegistry()
+	if err := registry.RegisterFallbackProfileFS(fstest.MapFS{
+		"first/profiles/one.yaml": {Data: []byte("id: one\nmodel: first\n")},
+	}, "first/profiles"); err != nil {
+		t.Fatalf("RegisterFallbackProfileFS() error = %v, want nil", err)
+	}
+	if err := registry.RegisterFallbackProfileFS(fstest.MapFS{
+		"second/two.yaml": {Data: []byte("id: two\nmodel: second\n")},
+	}, "second"); err != nil {
+		t.Fatalf("RegisterFallbackProfileFS() error = %v, want nil", err)
+	}
+
+	fallbackFS, err := registry.FallbackProfileFS()
+	if err != nil {
+		t.Fatalf("FallbackProfileFS() error = %v, want nil", err)
+	}
+	for _, name := range []string{"one.yaml", "two.yaml"} {
+		if _, err := fs.ReadFile(fallbackFS, name); err != nil {
+			t.Fatalf("FallbackProfileFS().ReadFile(%q) error = %v, want nil", name, err)
+		}
+	}
+}
+
+func TestAssetRegistryRejectsInvalidFallbackProfileRoot(t *testing.T) {
+	registry := NewAssetRegistry()
+	err := registry.RegisterFallbackProfileFS(fstest.MapFS{}, "../profiles")
+	if err == nil || !strings.Contains(err.Error(), "invalid path") {
+		t.Fatalf("RegisterFallbackProfileFS() error = %v, want invalid root error", err)
+	}
+}
+
+func TestAssetRegistryRejectsUnreadableFallbackProfileAssets(t *testing.T) {
+	registry := NewAssetRegistry()
+	if err := registry.RegisterFallbackProfileFS(unreadableAssetFS{}, "."); err != nil {
+		t.Fatalf("RegisterFallbackProfileFS() error = %v, want nil", err)
+	}
+	_, err := registry.FallbackProfileFS()
+	if err == nil || !strings.Contains(err.Error(), "permission denied") {
+		t.Fatalf("FallbackProfileFS() error = %v, want unreadable asset error", err)
+	}
+}
+
+func TestAssetRegistryRejectsDuplicateFallbackProfilePaths(t *testing.T) {
+	registry := NewAssetRegistry()
+	if err := registry.RegisterFallbackProfileFS(fstest.MapFS{"first/profile.yaml": {Data: []byte("id: first\n")}}, "first"); err != nil {
+		t.Fatal(err)
+	}
+	if err := registry.RegisterFallbackProfileFS(fstest.MapFS{"second/profile.yaml": {Data: []byte("id: second\n")}}, "second"); err != nil {
+		t.Fatal(err)
+	}
+	_, err := registry.FallbackProfileFS()
+	if err == nil || !strings.Contains(err.Error(), "duplicate asset path") {
+		t.Fatalf("FallbackProfileFS() error = %v, want duplicate path error", err)
+	}
+}
+
+func TestAssetRegistryFallbackProfileDigestTracksContentWithoutLeakingIt(t *testing.T) {
+	digestFor := func(content string) string {
+		t.Helper()
+		registry := NewAssetRegistry()
+		if err := registry.RegisterFallbackProfileFS(fstest.MapFS{
+			"profiles/profile.yaml": {Data: []byte(content)},
+		}, "profiles"); err != nil {
+			t.Fatal(err)
+		}
+		digest, err := registry.FallbackProfileDigest()
+		if err != nil {
+			t.Fatal(err)
+		}
+		return digest
+	}
+
+	first := digestFor("id: fallback\nmodel: model-one\n")
+	second := digestFor("id: fallback\nmodel: model-two\n")
+	if first == second {
+		t.Fatalf("fallback profile digests = %q and %q, want content change", first, second)
+	}
+	if !strings.HasPrefix(first, "sha256:") || strings.Contains(first, "model-one") || strings.Contains(first, "profile.yaml") {
+		t.Fatalf("fallback profile digest leaked source details: %q", first)
+	}
+}
+
 func TestAssetRegistryCombinesNamespacedPromptSources(t *testing.T) {
 	registry := NewAssetRegistry()
 	mustRegisterPromptFS(t, registry, fstest.MapFS{
@@ -196,3 +280,9 @@ output:
   repair_attempts: 0
 `
 }
+
+type unreadableAssetFS struct{}
+
+func (unreadableAssetFS) Open(name string) (fs.File, error) {
+	return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrPermission}
+}