feat: adiciona pagina de configuracoes, tema claro/escuro e corrige loop de login

src/main/java/com/agendaestudantil/configuracao/ResourceController.java

@@ -0,0 +1,23 @@
+package com.agendaestudantil.configuracao;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@Controller
+public class ResourceController {
+
+    @GetMapping("/")
+    public String index() {
+        return "forward:/login.html";
+    }
+
+    @GetMapping("/app")
+    public String app() {
+        return "forward:/calendario.html";
+    }
+
+    @GetMapping("/config")
+    public String config() {
+        return "forward:/configuracoes.html";
+    }
+}