Add dark mode, dyslexic font, and color blind accessibility features

[ErencemOzbey]

Add Comprehensive Accessibility Features — Dark Mode, Dyslexic Font, and Color Blind Support

📋 Overview

This PR introduces a complete accessibility suite to the HeatH mobile app, making it inclusive for users with diverse needs — including visual impairments, reading difficulties, and different usage preferences.

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✨ New Features

🌙 Dark Mode Support

• Full theme switching across all app pages
• Persistent user preference via AsyncStorage
• Dynamic color system adapting all UI elements
• Reduces eye strain for late-night users
• Professional dark theme with WCAG-compliant contrast ratios

🔤 Dyslexic Font Support

• OpenDyslexic font integration for improved readability
• Font toggle with real-time visual feedback
• Dynamic font switching across all text elements
• Adjusted line heights to prevent text cropping
• Accessibility-focused button placement for better reachability

🎨 Color Blind Accessibility

• Dedicated Color Blind Mode toggle (🎨 / 👓)
• Green-to-blue transformation for better distinction
• High-contrast color palette for improved visibility
• Full UI adaptation via dynamic color system
• Visual demo section to preview color accessibility effects

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⚙️ Core Architecture

• Context-based state management for theme & preferences
• Dynamic styling system replacing static color references
• Persistent storage for user accessibility settings
• Cross-component theming for consistent color and typography

🎯 User Scenarios Supported

1. University Student (Dark Mode)
   “Sarah studies late at night and prefers a dark interface that reduces eye strain during midnight cooking sessions.”

2. Dyslexic User (Font Support)
   “Emma struggles with traditional fonts but can easily read recipes in the OpenDyslexic font.”

3. Color Blind User (Color Accessibility)
   “David, with red-green color blindness, can now easily distinguish success (blue) and error (red) states.”

4. General Users (Enhanced UX)
   “All users benefit from a customizable interface that adapts to their visual and accessibility preferences.”

📊 Impact

Accessibility Improvements:

• 🔹 Dark mode for low-light usability
• 🔹 Readability boost for dyslexic users
• 🔹 Better color distinction for color-blind users
• 🔹 Stronger inclusivity & user satisfaction

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✅ Result: HeatH mobile app is now more inclusive, customizable, and user-friendly, supporting accessibility for all.

[YigitMemceroktay]

Great changes! Thank you for your effort. The conflicts are now resolved and the updates are ready to be merged.