R-66: the box's own address becomes visible (v0.159.0)

Leg A: „Hálózat" card on Beállítások → Rendszer — Helyi cím (LAN),
Hálózati név (only while Megosztás is enabled), Átjáró; live per render,
stored nowhere (S-5), „—" on unavailable.
Leg B: network section in the Debug system dump (interfaces/route/DNS/
lan_address), best-effort per item via the samba-netns door.
Leg C: NetBIOS trap named — Szerver field helper text + a purely lexical
hint on unreachable failures for single-label non-IP names.

Design note: all guest-net reads go through docker exec into the
host-networked felhom-samba container (stacks/guestnet.go, one seam) —
the controller's own netns is the docker bridge, so /proc/net/route etc.
would answer 172.x (the S-2 trap). Red-proofs: A2 gate-drop and C2
lexical-invert both failed as required.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UuFPHmHNrCJj1VhY6QdDMU

controller/internal/web/sharing_handlers.go

@@ -199,6 +199,35 @@ func (s *Server) sambaLANAddress() string {
 	return s.stackMgr.SambaLANAddress()
 }
 
+// guestGateway resolves the guest's default gateway for the Hálózat card (R-66) — the sibling of
+// sambaLANAddress with the identical contract: live per render, never stored, "" = the row shows
+// „—". The read goes through the samba-container netns door (stacks/guestnet.go) because the
+// controller's OWN /proc/net/route answers for the docker bridge (172.x) — the S-2 wrong answer.
+func (s *Server) guestGateway() string {
+	if s.guestGatewayFn != nil {
+		return s.guestGatewayFn()
+	}
+	if s.stackMgr == nil {
+		return ""
+	}
+	return s.stackMgr.GuestGateway()
+}
+
+// guestNetSnapshot resolves the Debug dump's network section (R-66); same seam shape.
+func (s *Server) guestNetSnapshot() stacks.GuestNetSnapshot {
+	if s.guestNetFn != nil {
+		return s.guestNetFn()
+	}
+	if s.stackMgr == nil {
+		return stacks.GuestNetSnapshot{Errors: map[string]string{
+			"interfaces": "stack manager unavailable",
+			"route":      "stack manager unavailable",
+			"dns":        "stack manager unavailable",
+		}}
+	}
+	return s.stackMgr.GuestNetSnapshot()
+}
+
 func (s *Server) sharingPageHandler(w http.ResponseWriter, r *http.Request) {
 	data := s.sharingPageData()
 	if f := strings.TrimSpace(r.URL.Query().Get("flash")); f != "" {