You are a professional Python desktop app developer.  
Create a professional-grade, well-structured, maintainable Python desktop application called "Automated PC Maintenance Scheduler" with the following requirements:

1. Use PyQt5 for the GUI with a clean, modern, and intuitive interface focused on excellent UX. The UI should have:
   - A main dashboard showing system maintenance status, last run, and next scheduled run
   - A section for selecting maintenance tasks:
       * Temp file cleanup
       * Recycle Bin emptying
       * Disk defragmentation (Windows only)
       * Memory optimization
   - A schedule setup panel allowing users to choose schedule intervals: daily, weekly, monthly
   - A manual "Run Maintenance Now" button
   - Status and progress notifications inside the app
   - Logs viewer showing details of maintenance runs and errors
   
2. Implement maintenance functionalities:
   - Code for temp files cleanup using Python's tempfile and os modules
   - Recycle bin empty functionality using Windows PowerShell commands (run via subprocess)
   - Disk defragmentation using the Windows defrag command-line utility (run via subprocess)
   - Simple memory cleanup (simulate or use platform-specific commands)
   
3. Implement task scheduling using APScheduler running in the background.

4. Implement a license activation system with:
   - Online license key verification using Google Drive as a free license server (simulate or implement basic verification reading license keys from a public Google Sheet or a public JSON file hosted on Google Drive)
   - License types: 1 month, 6 months, and 1 year expiry period
   - License validation on app startup and before running maintenance tasks
   - Automatic license expiration handling with UI feedback
   
5. Include proper error handling and logging with log files stored locally.

6. Display developer details in About section:
   - Developer name: Harsh Computronics
   - Contact email: <PRESIDIO_ANONYMIZED_EMAIL_ADDRESS>
   - Website: hcomputronics.com

7. Package the app structure professionally with separation of concerns (UI, backend logic, scheduler, licensing).

8. Include code comments and docstrings for readability and easy maintenance.

9. Provide instructions (as comments or docstring) for packaging the app into a Windows executable using PyInstaller or similar.

10. The app should be extensible and well prepared for future feature additions.

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Generate the full project starter code including:

- main.py containing the application entry point and initialization
- ui_main.py or within main.py the PyQt5 window and widgets setup conforming to modern UI standards
- maintenance.py module with maintenance task implementations
- scheduler.py module for scheduled task management using APScheduler
- license_manager.py module to handle license activation, online license key validation, expiry management
- logger.py module for logging maintenance and app events
- README.md with developer contact, app description, and packaging instructions

Make sure the code is professional quality, with comments explaining significant blocks.

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At the end, please also generate a usage guide describing how to:

- Run the app from source
- Activate the license (overview of how it works)
- Schedule maintenance tasks
- Build an EXE installer with PyInstaller

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Developer details:

Harsh Computronics  
<PRESIDIO_ANONYMIZED_EMAIL_ADDRESS>  
https://hcomputronics.com

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Please produce the complete project as separate code blocks or labeled file outputs.