Adds authentication and improves environment setup

Introduces new environment variables for authentication services:
BETTER_AUTH_URL, BETTER_AUTH_SECRET, GOOGLE_CLIENT_ID, and GOOGLE_CLIENT_SECRET.

Marks environment variables evaluation and Biome tasks as completed in the TODO list.

Enhances overall security and readiness for implementing authentication features.

Author: MichielOlijslagers

TODO.md

@@ -24,9 +24,9 @@
 - Dev experience
   - [ ] Dev tools
     - https://react-router-devtools.forge42.dev/
-  - [ ] Env variables evaluation
+  - [x] Env variables evaluation
     - https://dane.computer/blogs/type-safe-environment-variables-in-remix
-  - [ ] Biome
+  - [x] Biome
     - https://biomejs.dev/
 
 # Some useful resources that can improve this project

app/lib/env.server.ts

@@ -3,6 +3,10 @@ import { z } from "zod";
 const schema = z.object({
   NODE_ENV: z.enum(["production", "development", "test"] as const),
   DATABASE_URL: z.string(),
+  BETTER_AUTH_URL: z.string(),
+  BETTER_AUTH_SECRET: z.string(),
+  GOOGLE_CLIENT_ID: z.string(),
+  GOOGLE_CLIENT_SECRET: z.string(),
 });
 
 declare global {