Re-add user impersonation

[MayaRainer]

Now that Clerk is gone, we no longer have a way of impersonating users on Flexile to debug issues. Would be good to re-add as it saves a lot of time doing support.

[slavingia]

Cancelled clerk to save $225 a month :D

[Nainish-Rai]

How are we going to fix this?

[slavingia]

An MVP approach may be to run a console command like user.generate_impersonation_url, which generates a URL that the user can then paste in their browser. It would only work for admin users.

(Same with companies which would generate a URL for the primary admin)

[plyght]

@slavingia any bounty $ on this?

[namanxajmera]

@MayaRainer I've implemented the user impersonation feature you requested in PR #830.

What's Delivered

Simple Console Command (as requested by @slavingia):

rails impersonation:generate_url[user@example.com]
# Output: https://flexile.co/admin/impersonate?token=AbCdEf...

Key Features:

• ✅ Admin-only access - Uses existing team_member? constraint
• ✅ Secure - 5-minute expiring signed tokens
• ✅ Simple workflow - Console command → paste URL → impersonate user
• ✅ Stop anytime - DELETE endpoint to restore original admin user
• ✅ JWT compatible - Extends existing auth to support browser cookies

Why This Approach

This delivers the MVP console command approach @slavingia suggested instead of the complex web UI in PR #797. It's:

• Minimal - <100 lines of core logic vs 200+
• Secure - Uses Rails signed IDs + existing admin routes
• Fast to implement - Extends current JWT auth instead of new systems

Usage

1. Admin runs: rails impersonation:generate_url[user@example.com]
2. Pastes generated URL in browser
3. System switches admin to impersonate that user
4. Admin can debug issues as the user
5. Visit /admin/impersonate (DELETE) to stop impersonation

The implementation includes comprehensive tests, documentation, and error handling for all edge cases.

Ready for review! This should solve your support debugging needs with minimal complexity.

[jacquez-bot]

This comment is missing a reference to the related issue or PR. Please include 'Closes #XXX' or 'Fixes #XXX' to link to the issue this addresses.

[AJ0070]

This delivers the MVP console command approach @slavingia suggested instead of the complex web UI in PR #797.

FYI I haven't used UI in my implementation if you do have a look at it carefully.