feat: improve email status querying and URL handling

- Updated email status query to execute only when there are email IDs, enhancing performance.
- Ensured URL handling in email sending functions always includes a protocol, improving reliability.
- Added new queries for fetching emails by IDs and listing scheduled emails, enriching email management capabilities.

packages/backend/convex/chat.ts

@@ -440,7 +440,12 @@ export const enviarMensagem = mutation({
               const usuarioParticipante = await ctx.db.get(participanteId);
               if (usuarioParticipante?.email) {
                 // Obter URL do sistema (padrão: localhost para dev)
-                const urlSistema = process.env.FRONTEND_URL || "http://localhost:5173";
+                let urlSistema = process.env.FRONTEND_URL || "http://localhost:5173";
+                
+                // Garantir que a URL sempre tenha protocolo
+                if (!urlSistema.match(/^https?:\/\//i)) {
+                  urlSistema = `http://${urlSistema}`;
+                }
                 
                 ctx.scheduler.runAfter(1000, api.email.enviarEmailComTemplate, {
                   destinatario: usuarioParticipante.email,