refact: 5th cycle

[pftg]

Summary by CodeRabbit

• New Features

  • New alert variants, navigation component with dropdowns/mobile controls, button styles, PowerPack tabs/list/content-grid, testimonial slider, critical header styles.

• Improvements

  • Consolidated foundational utilities (reset/clearfix/flexbox/display/margins/padding/position/visibility), color variables, lighter critical CSS, component bundling, simplified DOM class usage.

• Removals

  • Several legacy component styles removed (cards, grid, pagination, typography, accordion, footer, contact, service-grid, team) and many legacy docs.

• Tests

  • Added a homepage screenshot retry and a template-preservation validation test.