feat: add t3app well-known playground routing

.changeset/clever-numbers-swim.md

@@ -0,0 +1,5 @@
+---
+"create-t3-app": minor
+---
+
+Add t3app well-known playground routing

cli/src/helpers/createProject.ts

@@ -9,6 +9,7 @@ import {
   selectIndexFile,
   selectLayoutFile,
   selectPageFile,
+  selectWellknown3AppFiles,
 } from "~/helpers/selectBoilerplate.js";
 import {
   type DatabaseProvider,
@@ -69,6 +70,7 @@ export const createProject = async ({
     );
 
     selectLayoutFile({ projectDir, packages });
+    selectWellknown3AppFiles({ projectDir, packages });
     selectPageFile({ projectDir, packages });
   } else {
     selectAppFile({ projectDir, packages });

cli/src/helpers/selectBoilerplate.ts

@@ -63,6 +63,18 @@ export const selectLayoutFile = ({
   fs.copySync(appSrc, appDest);
 };
 
+// Adds the .well-known/t3app folder to the project
+export const selectWellknown3AppFiles = ({
+  projectDir,
+}: SelectBoilerplateProps) => {
+  const appSrc = path.join(
+    PKG_ROOT,
+    "template/extras/src/app/.well-known/t3app"
+  );
+  const appDest = path.join(projectDir, "src/app/.well-known/t3app");
+  fs.copySync(appSrc, appDest);
+};
+
 // This selects the proper index.tsx to be used that showcases the chosen tech
 export const selectIndexFile = ({
   projectDir,

cli/template/extras/src/app/.well-known/t3app/playground/.gitignore

@@ -0,0 +1 @@
+*

cli/template/extras/src/app/.well-known/t3app/playground/page.tsx

@@ -0,0 +1,3 @@
+export default function Playground() {
+  return <h1>Hello, Playground!</h1>;
+}