feat: implement StaticContentCleaner and update theme build commands

[dermatz]

Automatic Static File Cleaning in Developer Mode

Problem

In developer mode, Magento generates static files on-demand which can conflict with theme builder outputs. This leads to inconsistent styling and cached assets that don't reflect the latest theme changes.

Solution

Implemented automatic cleaning of theme-specific static files before build/watch operations when running in developer mode.

Key Changes:

• ThemeCleaner Service: Centralized service for all theme cleaning operations (eliminates code duplication)
• StaticContentCleaner Service: Detects developer mode and automatically cleans:
  • pub/static/frontend/{Vendor}/{theme}/
  • var/view_preprocessed/css/frontend/{Vendor}/{theme}/
  • var/view_preprocessed/source/frontend/{Vendor}/{theme}/
• Builder Integration: All three builders (HyvaThemes, MagentoStandard, TailwindCSS) now use StaticContentCleaner
• CleanCommand Refactoring: Refactored to use ThemeCleaner service (~210 lines of duplicate code removed)

Behavior:

• ✅ Automatic cleaning only in developer mode
• ✅ Silent in normal mode, verbose output with -v flag
• ✅ Works for both build and watch commands
• ✅ Manual cleaning still available via mageforge:theme:clean