pricing: remove monthly/yearly billing toggle, default to yearly

- Remove billing-toggle-wrap HTML (switch + labels)
- Update all 4 pricing cards to show yearly prices by default
  with / year period and save percentage
- Simplify openOrderWidget() to always use yearly pricing only
- Remove billing toggle JS block (updatePrices, setBilling, event listeners)
- Remove billing toggle CSS (billing-toggle-wrap, .toggle-*, .toggle-switch)
- Update order widget default display to / year
- Update CTA note to 'Save money, less administration'

style.css

@@ -626,53 +626,6 @@ img { max-width: 100%; height: auto; vertical-align: middle; }
   color: var(--success);
   margin-top: 0.15rem;
 }
-/* Billing Toggle */
-.billing-toggle-wrap {
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  gap: 0.75rem;
-  margin-bottom: 1.5rem;
-}
-.toggle-label {
-  font-size: 0.82rem;
-  font-weight: 500;
-  color: rgba(255,255,255,0.5);
-  cursor: pointer;
-  transition: color 0.2s;
-  user-select: none;
-}
-.toggle-label.active { color: #fff; font-weight: 600; }
-.toggle-label small {
-  display: block;
-  font-size: 0.72rem;
-  font-weight: 500;
-  color: var(--success);
-  margin-top: 0.1rem;
-}
-.toggle-switch {
-  width: 48px;
-  height: 26px;
-  background: rgba(255,255,255,0.15);
-  border-radius: 13px;
-  cursor: pointer;
-  position: relative;
-  transition: background 0.25s;
-  flex-shrink: 0;
-}
-.toggle-switch.yearly { background: var(--brass); }
-.toggle-switch .thumb {
-  position: absolute;
-  top: 3px;
-  left: 3px;
-  width: 20px;
-  height: 20px;
-  background: #fff;
-  border-radius: 50%;
-  transition: left 0.25s;
-  box-shadow: 0 1px 3px rgba(0,0,0,0.15);
-}
-.toggle-switch.yearly .thumb { left: 25px; }
 .price-period { color: var(--ink-soft); font-size: 0.68rem; }
 .pricing-cta-note {
   text-align: center;