[UI/UX] MIND Tab - Wellbeing and Focus Hub

[ucguy4u]

Part of #187 - UI/UX Architecture Improvements

Tab Purpose

Wellbeing, reflection, guidance, light motivation

Required Changes

• Create new MindScreen (this is NOT the agent chat)
• Greeting Card (dismissible, time-based: Good morning/afternoon/evening)
• Daily Quote Card - ONLY place for quotes in the app
• Mind Actions section: Daily Insight, Breathing Exercise, Reflection
• Progress/Streak tracking UI
• Update router to point /mind to MindScreen

UX Rules

• This is the ONLY tab where greetings appear
• This is the ONLY tab where quotes/inspiration appear
• No music player visible

Files to Create/Modify

• Create: app/lib/features/mind/presentation/screens/mind_screen.dart
• Modify: app/lib/core/routing/app_router.dart