Refactor windowed mode and subprocess handling

Removed redundant windowed mode setup from main.py and simplified subprocess creation flags logic across core and GUI modules. Centralized subprocess creation flags usage, eliminated custom run_subprocess_hidden wrapper, and improved logging handler setup for better compatibility with windowed applications.

src/gui/ytsage_gui_main.py

@@ -1,6 +1,5 @@
 import json
 import subprocess
-import sys
 import threading
 import webbrowser
 from pathlib import Path
@@ -1736,21 +1735,7 @@ class YTSageApp(QMainWindow, FormatTableMixin, VideoInfoMixin):  # Inherit from
 
             # Execute command with hidden console window on Windows
             # Extra logic moved to src\utils\ytsage_constants.py
-            creation_flags = SUBPROCESS_CREATIONFLAGS
-            if getattr(sys, 'frozen', False):
-                # Running as compiled executable - use additional flags to prevent console flicker
-                creation_flags |= subprocess.CREATE_NEW_PROCESS_GROUP | subprocess.DETACHED_PROCESS
-            
-            result = subprocess.run(
-                cmd, 
-                capture_output=True, 
-                text=True, 
-                timeout=60, 
-                creationflags=creation_flags,
-                stdin=subprocess.DEVNULL,
-                stdout=subprocess.PIPE,
-                stderr=subprocess.PIPE
-            )
+            result = subprocess.run(cmd, capture_output=True, text=True, timeout=60, creationflags=SUBPROCESS_CREATIONFLAGS)
 
             if result.returncode != 0:
                 raise Exception(f"yt-dlp failed: {result.stderr}")