Initial project structure and core files

Add base project files including environment example, license, README, .gitignore, error classes, ESLint config, database modules, texture assets, repositories, routes, schemas, services, and server entry point. This establishes the foundational structure for a Yggdrasil-compatible REST API with modular error handling, database setup, and route organization.

schemas/register.js

@@ -0,0 +1,25 @@
+const z = require("zod")
+
+module.exports = {
+    POST: {
+        headers: z.object({
+            "content-type": z.string().regex(/application\/json/i)
+        }),
+        body: z.object({
+            email: z.string()
+                .email({ message: "Invalid E-Mail format." })
+                .toLowerCase(),
+            username: z.string()
+                .min(3, { message: "The username must be at least 3 characters long." })
+                .max(16, { message: "The username must be no longer than 16 characters." }),
+            password: z.string()
+                .min(8, { message: "The password must be at least 8 characters long." })
+                .regex(/[A-Z]/, { message: "The password must contain a capital letter." })
+                .regex(/[0-9]/, { message: "The password must contain a number." })
+        }),
+        error: {
+            code: 422,
+            message: "Invalid request data"
+        }
+    }
+}