task 00p: add -race to default test task; add t.Parallel() to safe unit tests

- Enable -race flag on the default 'task test' command so race conditions
  are caught by default, not only when running 'task test-race'
- Add t.Parallel() to all tests in internal/image/prompt_test.go (pure
  function tests with no shared state)
- Add t.Parallel() to TestReadBatchFile and its subtests in batch package
  (file I/O with t.TempDir(), no global state)
- Add t.Parallel() to TestValidateBulgarianText and its subtests in audio
  package (pure string validation, no shared state)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

4 files changed, 13 insertions, 2 deletions

diff --git a/Taskfile.yaml b/Taskfile.yaml
index f4588d1..2158167 100644
--- a/Taskfile.yaml
+++ b/Taskfile.yaml
@@ -8,9 +8,9 @@ tasks:
     cmds:
       - go run ./cmd/totalrecall
   test:
-    desc: Run all tests
+    desc: Run all tests with race detector
     cmds:
-      - go test ./...
+      - go test -race ./...
   
   test-verbose:
     desc: Run all tests with verbose output
diff --git a/internal/audio/validate_test.go b/internal/audio/validate_test.go
index 7bc3c9e..4b3392f 100644
--- a/internal/audio/validate_test.go
+++ b/internal/audio/validate_test.go
@@ -6,6 +6,7 @@ import (
 )
 
 func TestValidateBulgarianText(t *testing.T) {
+	t.Parallel()
 	tests := []struct {
 		name    string
 		text    string
@@ -50,6 +51,7 @@ func TestValidateBulgarianText(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
 			err := ValidateBulgarianText(tt.text)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("ValidateBulgarianText() error = %v, wantErr %v", err, tt.wantErr)
diff --git a/internal/batch/processor_test.go b/internal/batch/processor_test.go
index 8bc8079..4ec1739 100644
--- a/internal/batch/processor_test.go
+++ b/internal/batch/processor_test.go
@@ -10,6 +10,7 @@ import (
 )
 
 func TestReadBatchFile(t *testing.T) {
+	t.Parallel()
 	tests := []struct {
 		name        string
 		fileContent string
@@ -136,6 +137,7 @@ func TestReadBatchFile(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
 			// Create temp file
 			tmpDir := t.TempDir()
 			tmpFile := filepath.Join(tmpDir, "test.txt")
@@ -157,6 +159,7 @@ func TestReadBatchFile(t *testing.T) {
 }
 
 func TestReadBatchFile_FileNotFound(t *testing.T) {
+	t.Parallel()
 	_, err := ReadBatchFile("/nonexistent/file.txt")
 	if err == nil {
 		t.Error("Expected error for non-existent file")
diff --git a/internal/image/prompt_test.go b/internal/image/prompt_test.go
index 1961ce2..41172e3 100644
--- a/internal/image/prompt_test.go
+++ b/internal/image/prompt_test.go
@@ -6,18 +6,21 @@ import (
 )
 
 func TestPromptSubjectUsesTranslationFirst(t *testing.T) {
+	t.Parallel()
 	if got := promptSubject(" apple ", "ябълка"); got != "apple" {
 		t.Fatalf("promptSubject() = %q, want %q", got, "apple")
 	}
 }
 
 func TestPromptSubjectFallsBackToOriginalWord(t *testing.T) {
+	t.Parallel()
 	if got := promptSubject("   ", "ябълка"); got != "ябълка" {
 		t.Fatalf("promptSubject() = %q, want %q", got, "ябълка")
 	}
 }
 
 func TestSanitizeSceneDescriptionRemovesLabelsAndFences(t *testing.T) {
+	t.Parallel()
 	scene := "```text\nScene: A bright apple sits centered on a wooden table.\n```"
 	if got := sanitizeSceneDescription(scene); got != "A bright apple sits centered on a wooden table" {
 		t.Fatalf("sanitizeSceneDescription() = %q", got)
@@ -25,6 +28,7 @@ func TestSanitizeSceneDescriptionRemovesLabelsAndFences(t *testing.T) {
 }
 
 func TestUsableSceneDescriptionRejectsTrivialContent(t *testing.T) {
+	t.Parallel()
 	if usableSceneDescription("A") {
 		t.Fatal("usableSceneDescription() unexpectedly accepted trivial scene")
 	}
@@ -34,6 +38,7 @@ func TestUsableSceneDescriptionRejectsTrivialContent(t *testing.T) {
 }
 
 func TestFallbackVisualDirectionForPhrase(t *testing.T) {
+	t.Parallel()
 	got := fallbackVisualDirection("to indulge someone")
 	if got == "" || !usableSceneDescription(got) {
 		t.Fatalf("fallbackVisualDirection() returned unusable phrase direction: %q", got)
@@ -41,6 +46,7 @@ func TestFallbackVisualDirectionForPhrase(t *testing.T) {
 }
 
 func TestFallbackVisualDirectionForSingleWord(t *testing.T) {
+	t.Parallel()
 	got := fallbackVisualDirection("apple")
 	if got == "" || !strings.Contains(got, "single apple") {
 		t.Fatalf("fallbackVisualDirection() = %q", got)