fix(auth): prevent authenticated route access after logout

[navaneeth0041]

Description

This PR addresses a security vulnerability in the logout flow where users could access authenticated screens after logout by using the back button. The fix replaces context.push() with context.go() to properly clear the navigation stack upon logout.

Motivation:

• Prevent unauthorized access to protected routes after logout
• Improve security by ensuring proper session termination
• Follow best practices for handling authentication state

Dependencies:

• No new dependencies required
• Uses existing go_router package

Fixes #246

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Manual testing performed with the following test cases:

1. Logout flow:
   • Navigate to settings
   • Click logout
   • Verify redirect to login screen
   • Attempt to use back button
   • Verify unable to access previous authenticated screens

WhatsApp.Video.2025-01-28.at.18.19.43.mp4

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have checked my code and corrected any misspellings
• The commit message follows the project's commit convention
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Maintainer Checklist

• closes Fix: Prevent access to authenticated routes after logout via back button #246
• Tag the PR with: security, auth, bugfix

[mdmohsin7]

lgtm