Implement user-configurable settings with enhanced UI

Configuration Changes:
- Store config.ini in platform-specific user directories
  - macOS: ~/Library/Application Support/MSMD/
  - Windows: %APPDATA%\MSMD\
  - Linux: ~/.config/MSMD/
- Automatically create default config on first run
- Config file now editable and persists across app updates

Settings Dialog Enhancements:
- Add "Show Reference Creator" checkbox to Settings UI
- All settings now configurable through UI (no manual editing required)
- Settings dialog dynamically updates reference creator button visibility

Technical Implementation:
- Add getUserConfigDir(), getConfigFilePath(), createDefaultConfig() helper functions
- Update readConfig() and writeConfig() to use user config location
- Enhanced Settings.py with QCheckBox for showReferenceCreator
- Automatic config migration from old location (if exists)

Documentation:
- Update README with config file locations
- Document both UI and manual configuration methods
- Update troubleshooting section

This resolves the bundled app config.ini issue - config is now user-writable and survives app updates.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

README.md

@@ -151,7 +151,30 @@ Add sound effects by placing WAV files named `sound0.wav`, `sound1.wav`, etc., i
 
 ## Configuration
 
-Edit `config.ini` to customize robot behavior:
+MSMD Player stores its configuration in a platform-specific user directory:
+
+- **macOS**: `~/Library/Application Support/MSMD/config.ini`
+- **Windows**: `%APPDATA%\MSMD\config.ini`
+- **Linux**: `~/.config/MSMD/config.ini`
+
+A default configuration file is automatically created on first run.
+
+### Changing Settings
+
+**Option 1: Settings Dialog (Recommended)**
+
+Click the Settings button (gear icon) in the main window to open the Settings dialog. All configuration options can be changed through the UI:
+- Upgrade Trigger (Hotspot or Level)
+- Upgrade Mode (Both, Left, Right, or Distance)
+- Minimum Power to Move (0-255)
+- Maximum Power to Move (0-255)
+- Show Reference Creator checkbox
+
+Changes are saved immediately when you click "Set".
+
+**Option 2: Manual Edit**
+
+You can also manually edit the `config.ini` file:
 
 ```ini
 [robot]
@@ -162,6 +185,8 @@ maxpowertomove = 95         # Maximum power (0-255)
 showReferenceCreator = 0    # Show reference creator button (0 or 1)
 ```
 
+Restart the application for manual changes to take effect.
+
 ### Configuration Options
 
 - **upgradetrigger**: When to upgrade robot power
@@ -361,7 +386,11 @@ See project repository for license information.
 ## Troubleshooting
 
 ### "Config.ini was not found"
-Create a `config.ini` file in the project root using the configuration template above.
+This error should not occur as the config file is created automatically on first run. If you see this error:
+- Check that the application has write permissions to the user config directory
+- On macOS: `~/Library/Application Support/MSMD/`
+- On Windows: `%APPDATA%\MSMD\`
+- On Linux: `~/.config/MSMD/`
 
 ### "hotspots.json does not exist"
 Ensure your content folder contains a valid `hotspots.json` file with entries for each image.