Fix build issues and improve grayscale filter discoverability

[alexwilson1]

Pull Request Summary

Thank you for creating such an awesome project! DetoxDroid is a fantastic tool for digital wellness, and I'm excited to contribute these improvements.

🚀 Main Changes

1. Simplified Signing Configuration

• Moved from third-party dependency (ilharp/sign-android-release@nightly) to direct Gradle configuration (simplification and remove a potential point of supply chain vulnerability).

2. Enhanced Grayscale Filter UX

• Made inclusion/exclusion list toggle more obvious and discoverable
• Added clear "Filter Mode" setting with "Exclude Apps" vs "Include Apps" options
• Integrated the toggle directly into the grayscale settings screen

3. Improved Build System

• Fixed builds for cold-started repos and forks
  • Enhanced CI/CD pipeline to handle initial releases properly
  • Better version bump logic and commit range analysis

4. Removed Root Functionality

• Eliminated third-party RootShell dependency (com.github.Stericson:RootShell:1.6)
• Dependency was unmaintained, potentially insecure, and causing build issues due to this new error
• Root users can typically run ADB commands anyway, so minimal benefit lost

5. Finer Grayscale Control

• Changed daily color screen time settings from 15-minute to 5-minute increments
• Allows for more precise user customization

I think that including third-party dependencies should be last resort, especially since the permissions requested by the app are so wide (required for it's functionality).