Add tests for main package, manager, and various components

- Introduced unit tests for the main package to ensure compilation.
- Added tests for the manager, including validation of upload sessions and handling of Blender binary paths.
- Implemented tests for job token generation and validation, ensuring security and integrity.
- Created tests for configuration management and database schema to verify functionality.
- Added tests for logger and runner components to enhance overall test coverage and reliability.

internal/database/schema_test.go

@@ -0,0 +1,58 @@
+package database
+
+import (
+	"database/sql"
+	"path/filepath"
+	"testing"
+)
+
+func TestNewDB_RunsMigrationsAndSupportsQueries(t *testing.T) {
+	dbPath := filepath.Join(t.TempDir(), "test.db")
+	db, err := NewDB(dbPath)
+	if err != nil {
+		t.Fatalf("NewDB failed: %v", err)
+	}
+	defer db.Close()
+
+	if err := db.Ping(); err != nil {
+		t.Fatalf("Ping failed: %v", err)
+	}
+
+	var exists bool
+	err = db.With(func(conn *sql.DB) error {
+		return conn.QueryRow("SELECT EXISTS(SELECT 1 FROM sqlite_master WHERE type='table' AND name='settings')").Scan(&exists)
+	})
+	if err != nil {
+		t.Fatalf("query failed: %v", err)
+	}
+	if !exists {
+		t.Fatal("expected settings table after migrations")
+	}
+}
+
+func TestWithTx_RollbackOnError(t *testing.T) {
+	dbPath := filepath.Join(t.TempDir(), "tx.db")
+	db, err := NewDB(dbPath)
+	if err != nil {
+		t.Fatalf("NewDB failed: %v", err)
+	}
+	defer db.Close()
+
+	_ = db.WithTx(func(tx *sql.Tx) error {
+		if _, err := tx.Exec("INSERT INTO settings (key, value) VALUES (?, ?)", "rollback_key", "x"); err != nil {
+			return err
+		}
+		return sql.ErrTxDone
+	})
+
+	var count int
+	if err := db.With(func(conn *sql.DB) error {
+		return conn.QueryRow("SELECT COUNT(*) FROM settings WHERE key = ?", "rollback_key").Scan(&count)
+	}); err != nil {
+		t.Fatalf("count query failed: %v", err)
+	}
+	if count != 0 {
+		t.Fatalf("expected rollback, found %d rows", count)
+	}
+}
+