fix: database tests for cache

internal/cache/cache_test.go

@@ -1,6 +1,8 @@
 package cache
 
 import (
+	"fmt"
+	"os"
 	"testing"
 	"time"
 
@@ -8,15 +10,16 @@ import (
 )
 
 func TestCache(t *testing.T) {
-	// Create temporary database for testing
-	database, err := db.New("test_cache.db")
+	// Create temporary database for testing with unique name
+	dbFile := fmt.Sprintf("test_cache_%d.db", time.Now().UnixNano())
+	database, err := db.New(dbFile)
 	if err != nil {
 		t.Fatalf("Failed to create test database: %v", err)
 	}
 	defer func() {
 		_ = database.Close()
 		// Clean up test database file
-		// os.Remove("test_cache.db")
+		_ = os.Remove(dbFile)
 	}()
 
 	// Create cache instance
@@ -76,6 +79,9 @@ func TestCache(t *testing.T) {
 	t.Run("Exists", func(t *testing.T) {
 		existsKey := "exists_key"
 
+		// Make sure the key doesn't exist initially by deleting it
+		_ = cache.Delete(existsKey)
+
 		// Should not exist initially
 		exists, err := cache.Exists(existsKey)
 		if err != nil {