refactor: move non-public routes to internal subfolder

"non-public" in this case means only used for event handling (and not supposed to be called by clients)

src/index.ts

@@ -34,14 +34,8 @@ app.route(
   await import("~/controllers/token").then((controller) => controller.default),
 );
 app.route(
-  "/upcoming-titles",
-  await import("~/controllers/upcoming-titles").then(
-    (controller) => controller.default,
-  ),
-);
-app.route(
-  "/new-episode",
-  await import("~/controllers/new-episode").then(
+  "/internal",
+  await import("~/controllers/internal").then(
     (controller) => controller.default,
   ),
 );