improve development authentication setup

- Replaced manual code commenting with environment variable controlled mock auth
- Added development env vars to VS Code launch.json for automatic mock authentication
- Removed unused LinkedIn provider import
- Authentication now automatically uses mock session when launched via VS Code debug
- Zero security impact on production (env vars only exist during debug sessions)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.vscode/launch.json

@@ -9,6 +9,11 @@
             "type": "node",
             "request": "launch",
             "envFile": "${workspaceFolder}/.env",
+            "env": {
+                "USE_MOCK_AUTH": "true",
+                "MOCK_USER_ID": "109754742613069927799",
+                "MOCK_USER_NAME": "Nikola Derežić"
+            },
             "runtimeArgs": [
                 "run", // this is `run` from `npm run`
                 "dev" // this is `dev` from `npm run dev`

app/lib/auth.ts

@@ -1,39 +1,25 @@
 import NextAuth, { NextAuthConfig } from 'next-auth';
 import GoogleProvider from 'next-auth/providers/google';
-import LinkedinProvider from 'next-auth/providers/linkedin';
+// import LinkedinProvider from 'next-auth/providers/linkedin';
 import { Session } from 'next-auth';
 import { AuthenticatedUser } from './types/next-auth';
 import { defaultLocale } from '../i18n';
 
 export const myAuth = () => {
+   // Use mock authentication in development when enabled via environment variable
+   if (process.env.NODE_ENV === 'development' && process.env.USE_MOCK_AUTH === 'true') {
+      const session: Session = {
+         user: {
+            id: process.env.MOCK_USER_ID || "109754742613069927799",
+            name: process.env.MOCK_USER_NAME || "Nikola Derežić",
+         },
+         expires: "123",
+      };
+      
+      return Promise.resolve(session);
+   }
 
-   /** 
+   return auth();
-   
-   Google auth does not work in development environment
-   - this is a hack to make it work in development environment
-   - it returns a fake session object which is used by the Next-Auth middleware
-
-   Instructions: when in dev environment, uncomment the following code snippet
-   - this will return a fake session object which is used by the Next-Auth middleware
-   - when in production environment, comment the code snippet back
-
-   Note: this is not a secure way to handle authentication, it is only for development purposes
-   - in production environment, the auth should be handled by the Next-Auth middleware
-
-   Code snippet:
-   
-   const session:Session = {
-      user: {
-         id: "109754742613069927799",
-         name: "Nikola Derežić",
-      },
-      expires: "123",
-   };
-   
-   return(Promise.resolve(session));
-   */
-
-   return(auth());
 }
 
 export const authConfig: NextAuthConfig = {