feat(app): added better auth for better auth stuff vs my home written broken one

app/src/internal/auth/routes/register.ts

@@ -0,0 +1,44 @@
+import { Router } from "express";
+import type { Request, Response } from "express";
+import z from "zod";
+import { auth } from "../../../pkg/auth/auth.js";
+
+const router = Router();
+
+const registerSchema = z.object({
+    email: z.email(),
+    name: z.string().min(2).max(100),
+    password: z.string().min(8, "Password must be at least 8 characters"),
+    username: z
+        .string()
+        .min(3)
+        .max(32)
+        .regex(/^[a-zA-Z0-9_]+$/, "Only alphanumeric + underscores"),
+    displayUsername: z.string().min(2).max(100).optional(), // optional in your API, but supported
+});
+
+router.post("/", async (req: Request, res: Response) => {
+    try {
+        // Parse + validate incoming JSON against Zod schema
+        const validated = registerSchema.parse(req.body);
+
+        // Call Better Auth signUp
+        const user = await auth.api.signUpEmail({
+            body: validated,
+        });
+
+        return res.status(201).json(user);
+    } catch (err) {
+        if (err instanceof z.ZodError) {
+            const flattened = z.flattenError(err);
+            return res.status(400).json({
+                error: "Validation failed",
+                details: flattened,
+            });
+        }
+        console.error(err);
+        return res.status(500).json({ error: "Internal server error" });
+    }
+});
+
+export default router;