feat(ux): toast system, accessible modal wrapper, safer dialogs

- Global toast stack (success/error/info) replacing hidden notice/syncError
- Shared Modal: focus trap, Escape, focus restore, scroll lock; all dialogs migrated
- ConfirmDialog tone prop; limit-override now warning-styled
- Single-entry delete now requires confirmation, per-row busy spinner
- Onboarding no longer closes on failed save; inline error + skip option

src/components/StatusRail.tsx

@@ -3,12 +3,11 @@ import type { SetupStatus } from "../types";
 
 type StatusRailProps = {
   busyAction: string | null;
-  syncError: string;
   setupStatus: SetupStatus;
 };
 
-export function StatusRail({ busyAction, syncError, setupStatus }: StatusRailProps) {
-  if (!busyAction && !syncError && setupStatus.state === "ok") return null;
+export function StatusRail({ busyAction, setupStatus }: StatusRailProps) {
+  if (!busyAction && setupStatus.state === "ok") return null;
   return (
     <div className="mt-3 grid gap-2">
       {busyAction && (
@@ -17,12 +16,6 @@ export function StatusRail({ busyAction, syncError, setupStatus }: StatusRailPro
           Working on {actionLabel(busyAction)}...
         </div>
       )}
-      {syncError && (
-        <div className="status-card status-card--error">
-          <AlertTriangle size={17} aria-hidden="true" />
-          {syncError}
-        </div>
-      )}
       {setupStatus.state === "error" && (
         <div className="status-card status-card--warning">
           <AlertTriangle size={17} aria-hidden="true" />