feat: implement dark mode toggle

[phsbrown]

✨ Descrição

Implementa funcionalidade de Dark Mode no aplicativo Blazor utilizando o suporte nativo do Bootstrap 5.3+.

📦 Alterações

Novos arquivos

• • Serviço para gerenciar estado do tema com persistência em localStorage
• • Componente de toggle com ícones sol/lua

Alterações existentes

• • Registro do ThemeService
• • Inicialização do tema
• • Adição do botão de toggle
• • Import do namespace Services

🎨 Como funciona

• O Bootstrap 5.3 suporta dark mode nativamente via atributo
• O ThemeService salva a preferência do usuário em
• O tema é aplicado automaticamente ao carregar a página

✅ Tasks da issue #1

• Adicionar estado de tema no app
• Criar componente de toggle
• Definir CSS para tema escuro (usando Bootstrap)
• Implementar persistência de preferência
• Aplicar tema escuro no layout principal

[phsbrown]

Code Review (Opus 4.6 / Codex 5.3)

Issues Found:

1. [HIGH] Theme icon doesn't update after toggle

• File:
• Problem: The component reads directly but doesn't subscribe to . After toggling, the icon won't update because the component won't re-render.
• Fix: Subscribe to the event and call .

2. [MEDIUM] Duplicate theme initialization

• File:
• Problem: JavaScript runs immediately AND runs after render. This is redundant.
• Fix: Remove one of them - recommend keeping only C# initialization for consistency.

3. [MEDIUM] Missing error handling for JS interop

• File:
• Problem: No try-catch around . If JS fails, app crashes.
• Fix: Add try-catch with fallback to default theme.

4. [LOW] Missing accessibility attribute

• File:
• Problem: Button has no for screen readers.
• Fix: Add .

[phsbrown]

Implementation Complete

Fixed all issues:

1. Theme icon update: Added implementation with event subscription and call.
2. Removed duplicate initialization: Simplified JS to just provide helper, C# handles all theme logic.
3. Added error handling: Wrapped in try-catch with fallback to light theme.
4. Added accessibility: Added to the button.

Changes made to:

• • Added event subscription and aria-label
• • Added try-catch error handling
• • Simplified JavaScript initialization