Admin tools: search, soft-hide, and staff inspect

[Geph]

Summary

Current /adminobservations covers list/near/info/remove/reactivate/teleport, but staff still lack good moderation workflow tools.

Suggested features

• Search by text substring, player name, and/or UUID
• Soft-hide (mark inactive) without hard purge
• Optional preview of inactive observations without temporary hologram clutter
• Staff click-to-inspect (view metadata) without forcing teleport-only UX