TaskyPad 1.0.9

Refactor initialization and enhance logging

Refactored `MainWindow` initialization to use asynchronous patterns, improving responsiveness and user experience. Introduced `_isInitialized` to ensure one-time async initialization. Replaced synchronous update checks with `InitializeAsync` and `CheckVersionAsync`.

Enhanced logging across the application using `Serilog`, adding detailed logs for `UpdateManager` operations and error handling. Improved robustness with better exception handling during update checks and application restarts.

Incremented `AssemblyVersion` to 1.0.9. Updated `README_LOGGING.md` to reflect new logging practices.