feat: track and display device token expiry in admin UI

[dirkwa]

Summary

• Store JWT exp claim as tokenExpiry on device records when approving access requests
• Display token expiry status in the R19 Devices page (table column + detail view) showing remaining time or an "Expired" badge
• Show badge counts on the Security sidebar menu: red for expired device tokens, green for pending access requests
• Fix Form.Control type="select" → Form.Select in AccessRequests to resolve React 19 error Handle error in certificate creation #137

Tested

• Approve a device access request with a short expiration (e.g. 60s) and verify tokenExpiry appears in the Devices table
• Verify expired tokens show a red "Expired" badge in both the table and detail view
• Verify the Security sidebar item shows a red badge for expired devices and a green badge for pending access requests
• Verify badges on the Security parent hide when the dropdown is expanded (children show their own)
• Verify the AccessRequests permissions dropdown works without React error Handle error in certificate creation #137

Images

[tkurki]

@sbender9 how does this look to you?

I often dislike human oriented time expressions and yearn for the exact time when something has happened / will happen. How about showing that on hover? Tiny detail, I know...

Another point would be to have "last seen" timestamp for tokens. Expiry is one thing, but last seen is often more valuable. Trouble is that would need persistence, and I don't want to complicate things with something like that right now, as I think we should start using node:sqlite and skserver.sqlite for stuff like this. So maybe file that for later, or another PR...