Add the Discover deck screen (mock 1a)

/discover now shows the Side quests deck: the "Discover" kicker and
"Side quests" title, the teal "Quest log · N" pill, and the three
stacked cards in a 440 px deck with perspective 1000px. The top card
shows the washed photo, the name, the difficulty dots and the
"Why this?" box, with hidden "Try it!" and "Pass" stamps. The 62 px
Pass and Try it buttons and the ←/→ keys all go through one decide
handler that ignores input while a decision is in flight.

An empty deck shows "All caught up" with "Get more now", which starts a
suggestion batch and shows skeleton cards while its job runs, reading
the deck again as the batch stores Side quests.

Maestro task 1ecc121c-86eb-4784-a9fb-1314709b4a59.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/discover/DiscoverPage.module.css

@@ -0,0 +1,264 @@
+/* Discover · Side quests (mock 1a). */
+.page {
+  box-sizing: border-box;
+  max-width: 440px;
+  display: flex;
+  flex-direction: column;
+  gap: 18px;
+  padding-top: 8px;
+}
+
+.header {
+  display: flex;
+  align-items: flex-end;
+  justify-content: space-between;
+  gap: 16px;
+}
+
+.kicker {
+  margin: 0;
+  font-family: var(--font-body);
+  font-size: 11px;
+  font-weight: 700;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: var(--color-accent-700);
+}
+
+.title {
+  margin: 0;
+  font-family: var(--font-heading);
+  font-size: 30px;
+  font-weight: 400;
+  line-height: 1.1;
+}
+
+/* The Quest log count pill. */
+.questLog {
+  flex: none;
+  padding: 7px 12px;
+  border-radius: var(--radius-pill);
+  background: var(--color-accent-2-200);
+  color: var(--color-accent-2-800);
+  font-family: var(--font-body);
+  font-size: 12px;
+  font-weight: 700;
+}
+
+/* The deck: three cards stacked in the same box, the top one in front. */
+.deck {
+  position: relative;
+  height: 440px;
+  perspective: 1000px;
+}
+
+.card {
+  position: absolute;
+  inset: 0;
+  box-sizing: border-box;
+  display: flex;
+  flex-direction: column;
+  border-radius: var(--radius-card);
+  overflow: hidden;
+  color: var(--color-text);
+}
+
+.depth0 {
+  z-index: 3;
+  transform: none;
+  background: var(--color-neutral-100);
+  box-shadow: var(--shadow-lg);
+}
+
+.depth1 {
+  z-index: 2;
+  transform: translateY(8px) scale(0.95);
+  background: var(--color-surface);
+}
+
+.depth2 {
+  z-index: 1;
+  transform: translateY(16px) scale(0.9);
+  background: var(--color-neutral-300);
+}
+
+.photo {
+  flex: none;
+  width: calc(100% - 20px);
+  height: 220px;
+}
+
+.content {
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+  padding: 4px 20px 0;
+}
+
+.name {
+  margin: 0;
+  font-family: var(--font-heading);
+  font-size: 24px;
+  font-weight: 400;
+  line-height: 1.1;
+}
+
+.difficulty {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  margin: 0;
+  font-family: var(--font-body);
+  font-size: 12px;
+  font-weight: 700;
+  color: var(--color-neutral-700);
+}
+
+.dots {
+  display: flex;
+  gap: 3px;
+}
+
+.dot,
+.dotFilled {
+  width: 8px;
+  height: 8px;
+  border-radius: var(--radius-pill);
+  background: var(--color-neutral-300);
+}
+
+.dotFilled {
+  background: var(--color-accent);
+}
+
+/* The "Why this?" box. */
+.why {
+  margin: 0;
+  padding: 12px 14px;
+  border-radius: 18px;
+  background: var(--color-accent-2-100);
+  color: var(--color-accent-2-900);
+  font-family: var(--font-body);
+  font-size: 13px;
+  line-height: 1.45;
+}
+
+/* The decision stamps, hidden until a decision shows them. */
+.stamp {
+  position: absolute;
+  top: 26px;
+  padding: 6px 14px;
+  border: 3px solid;
+  border-radius: 14px;
+  font-family: var(--font-heading);
+  font-size: 24px;
+  opacity: 0;
+  pointer-events: none;
+}
+
+.tryStamp {
+  left: 22px;
+  transform: rotate(-12deg);
+  border-color: var(--color-accent-2-700);
+  background: var(--color-accent-2-100);
+  color: var(--color-accent-2-800);
+}
+
+.passStamp {
+  right: 22px;
+  transform: rotate(12deg);
+  border-color: var(--color-neutral-800);
+  background: var(--color-neutral-100);
+  color: var(--color-neutral-900);
+}
+
+/* Pass and Try it: a 62 px circle over an 11 px label, one button each. */
+.actions {
+  display: flex;
+  justify-content: center;
+  gap: 28px;
+  margin-top: 4px;
+}
+
+.action {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 6px;
+  min-width: 62px;
+  min-height: 62px;
+  padding: 0;
+  border: 0;
+  background: none;
+  color: var(--color-neutral-700);
+  font-family: var(--font-body);
+  font-size: 11px;
+  font-weight: 700;
+  cursor: pointer;
+}
+
+.action:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+}
+
+.circle {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 62px;
+  height: 62px;
+  border-radius: var(--radius-pill);
+  box-shadow: var(--shadow-md);
+  transition: transform 100ms var(--ease-out-soft);
+}
+
+.action:active:not(:disabled) .circle {
+  transform: scale(0.97);
+}
+
+.pass {
+  background: var(--color-neutral-100);
+  color: var(--color-text);
+}
+
+.tryIt {
+  background: var(--color-accent-2-600);
+  color: var(--on-accent);
+}
+
+/* Skeleton cards while the deck loads or a batch finds Side quests. */
+.loading {
+  display: flex;
+  flex-direction: column;
+  gap: 22px;
+}
+
+.deck > .skeletonCard {
+  position: absolute;
+  inset: 0;
+  height: auto;
+  border-radius: var(--radius-card);
+}
+
+.skeletonCard.depth0,
+.skeletonCard.depth1,
+.skeletonCard.depth2 {
+  background: var(--color-surface);
+  box-shadow: none;
+}
+
+.finding {
+  margin: 0;
+  text-align: center;
+  font-family: var(--font-body);
+  font-size: 14px;
+  font-weight: 700;
+  color: var(--color-neutral-700);
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .circle {
+    transition: none;
+  }
+}