v0.310.0: „A gép kikapcsolása" — the household turns the whole machine off (R-998); honest restart text (R-999)

POST /api/server/poweroff (dashboard login, POST only, the typed word KIKAPCSOLÁS / TURN OFF)
→ agent POST /host/poweroff (MinAgent 0.155.0; hidden for an older agent). The controller refuses
during its own backup/restore/app update; the agent's reasons are shown as household sentences.
„Kiszolgáló újraindítása" becomes „A Felhom újraindítása" and says it restarts the Felhom part;
/api/server/reboot is POST only (R-983). Tests red-proofed; parity fixtures regenerated on purpose.

controller/internal/web/handlers.go

@@ -2346,6 +2346,7 @@ func (s *Server) systemPageData() map[string]interface{} {
 	}
 	// Guest RAM resize card (v0.143.0, R-24): current allocation + bounds + capability/reachability.
 	s.memoryCardData(data)
+	s.powerOffCardData(data) // R-998: hide „A gép kikapcsolása" only for a definitely-too-old agent
 
 	// „Hálózat" card (R-66): where the box IS, live-computed per render and stored NOWHERE — the
 	// guest holds its address by DHCP, so a stored copy eventually misdirects people (S-5); an