fix(toast): rename Nuxt UI 4 toast.add timeout → duration

Nuxt UI 4's Toast component reads `duration` (default 5000ms), not
`timeout` — the property was silently ignored. Behavior unchanged
since 5000ms matched the default. Fix the call site to be honest.

Strike the now-resolved gotcha from LAUNCH_READINESS.md.

app/components/SeriesPassPurchase.vue

@@ -308,7 +308,7 @@ const handleSubmit = async () => {
       title: "Series Pass Purchased!",
       description: `You're now registered for all ${purchaseResponse.registration.eventsRegistered} events in this series.`,
       color: "green",
-      timeout: 5000,
+      duration: 5000,
     });
 
     // Emit success event
@@ -328,7 +328,7 @@ const handleSubmit = async () => {
       title: "Purchase Failed",
       description: errorMessage,
       color: "red",
-      timeout: 5000,
+      duration: 5000,
     });
 
     emit("purchase-error", errorMessage);

docs/LAUNCH_READINESS.md

@@ -154,7 +154,6 @@ Context: Phase 4 audit against `docs/specs/events-visual-audit-findings.md` fixe
 - **Success-state color convention (4 instances).** "You're Registered!" blocks use `--candle` (gold) instead of `--green`. Touches `EventSeriesTicketCard.vue:186-196` (still uses phantom `candlelight-*` classes — preserved byte-for-byte pending decision) and registered-state wrappers in `SeriesPassPurchase.vue`. Needs a UX call on whether success should render gold (zine-consistent) or green (semantic). Once decided, finish the phantom-palette removal on those 4 lines.
 - **Sidebar breakpoint unverified.** `app/layouts/default.vue:89` hides the sidebar at ≤1024px per spec. Browser `resize_window` tool refused viewport changes during the audit, so the actual crossover and any layout shift at 1023–1025px was never visually confirmed. Do a manual responsive check before declaring the sidebar pattern shipped.
 - **`EventTicketPurchase.vue:469` magic padding.** `.consent-hint { padding-left: 24px; }` is a hardcoded offset to align the hint under the checkbox text. Cosmetic; swap for a gap/grid approach when touching the consent block next.
-- **Toast API rename unverified.** Nuxt UI v4 may have renamed `toast.add({ timeout })` → `{ duration }`. Current `SeriesPassPurchase.vue` toasts still pass `timeout`. No visible breakage, but worth confirming against current Nuxt UI docs.
 - **`.section-label` extraction candidate.** Several audited files repeat the same uppercase/letter-spaced small label pattern inline. Low-priority refactor into a utility class in `main.css`.
 - **Past-events toggle component.** Existing, untouched this pass; noted in findings doc as a future consistency check.