feat(settings): 2x2 grid for Node & Security (fills the card width)

Single-column left every row hugging the left with a blank right half (and a
split RPC row); two-column variants left a bottom-corner gap. Rework the card as
a 2x2 grid on wide full-node windows so both halves carry real content:
  TOP-LEFT NODE/Data | TOP-RIGHT RPC
  BOTTOM-LEFT SECURITY | BOTTOM-RIGHT DAEMON BINARY
with the two top cells sharing a row bottom, a thin vertical + horizontal
divider, and the Daemon "Advanced" destructive buttons dropping to a full-width
4-button strip below the grid when expanded.

Gated behind one `useGrid` flag (supportsFullNodeLifecycleActions() &&
availWidth >= node-grid-breakpoint, default 900). When false — narrow windows and
lite — it falls through to the existing single full-width column, unchanged
(one-flag-revertible). Wallet Size moved to its own row (removes a mid-row gap in
both layouts). RPC / Security / Daemon rebased to per-cell X/width via aliases;
Advanced buttons factored into one lambda so the disabled predicates live in a
single place. Design produced + adversarially critiqued via a multi-agent pass.

New: components.settings-page.node-grid-breakpoint (ui.toml), "rpc_connection"
i18n string. Full-node + lite build clean; ctest green; hygiene clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

res/themes/ui.toml

@@ -1325,6 +1325,7 @@ wallet-btn-padding = { size = 24.0 }
 rpc-label-min-width = { size = 70.0 }
 rpc-label-width = { size = 85.0 }
 security-combo-width = { size = 120.0 }
+node-grid-breakpoint = { size = 900.0 }
 port-input-min-width = { size = 60.0 }
 port-input-width-ratio = { size = 0.4 }
 idle-combo-width = { size = 64.0 }