Add recurring daily schedule controls

Replace the one-time renderer schedule form with recurring local time and start-day settings while preserving legacy schedule visibility.

Keep the toolbar slot mounted and inaccessible while closed, animate width, opacity, and horizontal position through the global motion preference, and add localized labels.

Surface activation and cancellation failures, reconcile the authoritative snapshot after failed writes, and cover the behavior with focused red-green tests.

src/renderer/views/downloads/downloads.css

@@ -237,13 +237,45 @@
   background: var(--ui-border);
 }
 
+.downloads-schedule-slot {
+  display: grid;
+  grid-template-columns: 0fr;
+  min-width: 0;
+  overflow: hidden;
+  opacity: 0;
+  pointer-events: none;
+  transition: grid-template-columns 180ms ease, opacity 140ms ease;
+}
+
+.downloads-schedule-slot.is-open {
+  grid-template-columns: 1fr;
+  opacity: 1;
+  pointer-events: auto;
+}
+
 .downloads-schedule-controls {
   display: flex;
   align-items: center;
   gap: 5px;
+  min-width: 0;
+  width: max-content;
+  overflow: hidden;
+  white-space: nowrap;
+  transform: translateX(-10px);
+  transition: transform 180ms ease;
 }
 
-.downloads-schedule-controls input {
+.downloads-schedule-slot.is-open .downloads-schedule-controls {
+  transform: translateX(0);
+}
+
+.downloads-schedule-slot.is-motion-disabled,
+.downloads-schedule-slot.is-motion-disabled .downloads-schedule-controls {
+  transition: none !important;
+}
+
+.downloads-schedule-controls input,
+.downloads-schedule-controls select {
   height: 36px;
 }