R-1112: open the family store when the controller starts

Found on demo-hp with 0.325.0-rc.1: the store (and so the conversion of an old family.json) opened only on the
first family request; a box nobody visits through a family gate kept the session values. OpenFamilyStore from
main, one INFO line with the count. TestR1112_StartConvertsTheFamilyFile, TestR1112_MainOpensTheFamilyStore,
red-proved.

Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/cmd/controller/main.go

@@ -2058,6 +2058,9 @@ func main() {
 	// Browser .fab upload (v0.128.0): upload state is in-memory, so a restart strands the .part —
 	// GC stray part files in every registered drive's exports dir at startup.
 	webServer.CleanupStaleUploadParts()
+	// R-1112: open (and convert) the family list now, not on the first family request — a box nobody visits through a
+	// family gate would otherwise keep session values on disk.
+	webServer.OpenFamilyStore()
 	// Escrow wizard (v0.127.0): the Scenario-F stale-blob flag feeds the Távoli mentés card.
 	if escrowConfirmer != nil {
 		webServer.SetEscrowStale(escrowConfirmer.StaleBlob)