feat: enhance ErrorModal and chat components with new features and improvements

- Refactored ErrorModal to utilize a dialog element for better accessibility and user experience, including a close button with an icon.
- Updated chat components to improve participant display and message read status, enhancing user engagement and clarity.
- Introduced loading indicators for user and conversation data in SalaReuniaoManager to improve responsiveness during data fetching.
- Enhanced message handling in MessageList to indicate whether messages have been read, providing users with better feedback on message status.
- Improved overall structure and styling across various components for consistency and maintainability.

packages/backend/convex/schema.ts

@@ -671,6 +671,7 @@ export default defineSchema({
     enviadaEm: v.number(),
     editadaEm: v.optional(v.number()),
     deletada: v.optional(v.boolean()),
+    lidaPor: v.optional(v.array(v.id("usuarios"))), // IDs dos usuários que leram a mensagem
   })
     .index("by_conversa", ["conversaId", "enviadaEm"])
     .index("by_remetente", ["remetenteId"])