Enhancement: theme polish & screen animations

[CoreyAllenAudio]

Context

The current theme is a basic dark scheme and transitions are minimal. Applying
the brand colors (#3) and adding tasteful motion will make the app feel intentional.

Scope

Refine the Compose theme with brand tokens and improve navigation/enter animations.
Visual/motion polish only — no new features or screens.

Tasks

• Apply brand color tokens from Design: Deskside brand & logo #3 to DeskTheme
• Review/refine dark color scheme for contrast + accessibility
• Improve screen transition animations (login → home, etc.)
• Ensure animations are consistent across screens

Acceptance Criteria

• Theme uses the brand colors from Design: Deskside brand & logo #3
• Transitions between core screens are smooth and consistent
• Text meets basic contrast on all backgrounds

Notes / design

Blocked until brand tokens exist (#3).