fix: replace emoji characters with ASCII-safe markers for Windows compatibility

- Replace Unicode emoji (✓, ⚠️) with [OK] and [WARN] in audio_preprocessor.py
  to prevent UnicodeEncodeError on Windows console (cp1252 codec)
- Add auto-update dependencies function to bot.py for easier maintenance
- Remove setup_linux.sh (no longer needed)
- Update .gitignore to exclude VS Code launch.json

bot.py

@@ -1,6 +1,8 @@
 import numba_config
 import asyncio
 import io
+import subprocess
+import sys
 import time
 from typing import Any
 
@@ -365,7 +367,27 @@ class TTSBot(commands.Bot):
             return None
 
 
+def auto_update_dependencies() -> None:
+    """Auto-update pip packages on startup."""
+    try:
+        print("Checking for package updates...")
+        result = subprocess.run(
+            [sys.executable, "-m", "pip", "install", "-r", "requirements.txt", "-U", "-q"],
+            capture_output=True,
+            text=True,
+            check=False
+        )
+        if result.returncode == 0:
+            print("Packages updated successfully (or already up to date)")
+        else:
+            print(f"Warning: Package update had issues: {result.stderr}")
+    except Exception as e:
+        print(f"Warning: Could not auto-update packages: {e}")
+
+
 def main():
+    auto_update_dependencies()
+
     errors = Config.validate()
     if errors:
         print("Configuration errors:")