refactor: create entity type directories on-demand instead of at init

Author: tyeongkim

internal/sync/sync_test.go

@@ -262,7 +262,11 @@ func TestForceRebuild_PartialParseFailure(t *testing.T) {
 
 	writeEntity(t, store, "REQ-001", model.EntityTypeRequirement, "Good entity", nil)
 
-	badPath := filepath.Join(root, "entities", "decision", "DEC-BAD.toml")
+	badDir := filepath.Join(root, "entities", "decision")
+	if err := os.MkdirAll(badDir, 0o755); err != nil {
+		t.Fatalf("create bad dir: %v", err)
+	}
+	badPath := filepath.Join(badDir, "DEC-BAD.toml")
 	if err := os.WriteFile(badPath, []byte("this is not valid toml [[["), 0o644); err != nil {
 		t.Fatalf("write bad file: %v", err)
 	}

internal/toml/loader.go

@@ -38,13 +38,10 @@ func (s *Store) HistoryPath(entityID string) string {
 	return filepath.Join(s.root, "history", entityID+".toml")
 }
 
-// Init creates the directory structure: entities/{type}/ for all entity types + history/.
 func (s *Store) Init() error {
-	for et := range model.TypePrefixMap {
-		dir := filepath.Join(s.root, "entities", string(et))
-		if err := os.MkdirAll(dir, 0o755); err != nil {
-			return fmt.Errorf("init entity dir %q: %w", dir, err)
-		}
+	entitiesDir := filepath.Join(s.root, "entities")
+	if err := os.MkdirAll(entitiesDir, 0o755); err != nil {
+		return fmt.Errorf("init entities dir: %w", err)
 	}
 
 	histDir := filepath.Join(s.root, "history")

internal/toml/loader_test.go

@@ -44,20 +44,24 @@ func TestStore_Init(t *testing.T) {
 		t.Fatalf("Init: %v", err)
 	}
 
+	entitiesDir := filepath.Join(root, "entities")
+	info, err := os.Stat(entitiesDir)
+	if err != nil {
+		t.Fatalf("expected entities dir to exist: %v", err)
+	}
+	if !info.IsDir() {
+		t.Fatalf("expected entities to be a directory")
+	}
+
 	for et := range model.TypePrefixMap {
 		dir := filepath.Join(root, "entities", string(et))
-		info, err := os.Stat(dir)
-		if err != nil {
-			t.Errorf("expected directory %s to exist: %v", dir, err)
-			continue
-		}
-		if !info.IsDir() {
-			t.Errorf("expected %s to be a directory", dir)
+		if _, err := os.Stat(dir); err == nil {
+			t.Errorf("expected per-type directory %s to NOT exist after Init (created on-demand)", dir)
 		}
 	}
 
 	histDir := filepath.Join(root, "history")
-	info, err := os.Stat(histDir)
+	info, err = os.Stat(histDir)
 	if err != nil {
 		t.Fatalf("expected history dir to exist: %v", err)
 	}