Let an operator edit a ticket's fields until it's applied or closed

Adds edit forms for Location, Client details (vorname/name/PTR/Package), Hardware, NICs (internal), Tenant (internal), and IXP (client) on the ticket detail page. Also closes a gap where the existing edit actions (edit-client, select-environment, select-preset, select-iso) had no status check at all, so they stayed live even on a closed ticket — every mutating ticket handler now requires status "open" server-side, with the template hiding the forms to match.

Co-Authored-By: Claude Sonnet 5 noreply@anthropic.com Claude-Session: https://claude.ai/code/session_01YAS8ojtevRQs2pGngj7D35