feat: add comprehensive diagnostic logging subsystem and UI controls

internal/fs-service/game-selection.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"g-launcher/pkg/logger"
 	"os"
 	"path/filepath"
 
@@ -43,10 +44,12 @@ func (f *FSService) GetSavedGameSelection() (string, string, error) {
 		return "", "", fmt.Errorf("parse saved game selection: %w", err)
 	}
 
+	logger.Info("GetSavedGameSelection: loaded GamePath=%s, GameDir=%s", selection.GamePath, selection.GameDir)
 	return selection.GamePath, selection.GameDir, nil
 }
 
 func (f *FSService) SaveGameSelection(gamePath, gameDir string) error {
+	logger.Info("SaveGameSelection: saving GamePath=%s, GameDir=%s", gamePath, gameDir)
 	path, err := gameSelectionPath()
 	if err != nil {
 		return err