v1.0.3

• Save log files to logs/ subfolder instead of app root directory
  (auto-created on first monitoring session)
• Add build.ps1: PowerShell build script that auto-detects Python,
  prompts for version, updates version.txt, installs dependencies
  (requirements.txt + PyInstaller), compiles a single-file .exe via
  PyInstaller and moves the result to exec/UsageMonitor-{version}.exe,
  then cleans up temporary build artifacts
• Rewrite README.md for public repository: English language, badges,
  full installation and usage instructions, updated project structure,
  build instructions for build.ps1, license and MAZNET author section