Add saved starter words for signed-in players

Players can save up to 3 favorite opening words and tap one to fill the
current row. Words are stored on profiles.starter_words and saved through
the set_starter_words RPC, which validates them against the dictionary.

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

CSS/styles.css

@@ -1015,6 +1015,123 @@ h2 {
   text-align: start;
 }
 
+.starter-panel {
+  display: grid;
+  gap: 12px;
+  max-width: 34rem;
+  margin-top: 28px;
+  padding: 16px 18px;
+  border: 1px solid var(--border);
+  border-radius: 20px;
+  background: color-mix(in oklch, var(--surface), var(--bg) 40%);
+}
+
+.starter-panel[hidden],
+.starter-editor[hidden],
+.starter-chips[hidden],
+.starter-panel .link-button[hidden] {
+  display: none;
+}
+
+.starter-head {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+}
+
+.starter-head .eyebrow {
+  margin: 0;
+}
+
+.starter-chips {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+}
+
+.starter-chips:empty {
+  display: none;
+}
+
+.starter-chip {
+  min-height: 44px;
+  padding: 0 16px;
+  border: 1px solid var(--border);
+  border-radius: 12px;
+  background: var(--tile);
+  color: var(--fg);
+  cursor: pointer;
+  font: inherit;
+  font-weight: 800;
+  letter-spacing: 0.14em;
+  text-transform: uppercase;
+  transition: transform 160ms ease, border-color 160ms ease, background-color 160ms ease;
+}
+
+.starter-chip:hover,
+.starter-chip:focus-visible {
+  transform: translateY(-1px);
+  border-color: var(--accent);
+  outline: none;
+}
+
+.starter-chip:active {
+  background: var(--key);
+}
+
+.starter-editor {
+  display: grid;
+  gap: 12px;
+}
+
+.starter-inputs {
+  display: grid;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 8px;
+}
+
+.starter-input {
+  min-width: 0;
+  min-height: 44px;
+  border: 1px solid var(--border);
+  border-radius: 12px;
+  background: var(--bg);
+  color: var(--fg);
+  font: inherit;
+  font-weight: 800;
+  letter-spacing: 0.12em;
+  text-align: center;
+  text-transform: uppercase;
+}
+
+.starter-input:focus {
+  border-color: var(--accent);
+  outline: none;
+  box-shadow: 0 0 0 3px color-mix(in oklch, var(--accent), transparent 75%);
+}
+
+.starter-input[aria-invalid] {
+  border-color: var(--accent);
+}
+
+.starter-editor-actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: 8px;
+}
+
+.starter-hint {
+  margin: 0;
+  color: var(--muted);
+  font-size: 0.9rem;
+  line-height: 1.5;
+}
+
+.starter-hint .link-button {
+  font-size: inherit;
+}
+
 @keyframes intro-tile-enter {
   0% {
     transform: translate3d(0, 34px, -180px);
@@ -1179,10 +1296,17 @@ h2 {
   }
 
   h1,
-  .deck {
+  .deck,
+  .starter-panel {
     margin-inline: auto;
   }
 
+  .starter-panel {
+    width: 100%;
+    margin-top: 18px;
+    text-align: start;
+  }
+
   .deck {
     margin-top: 12px;
   }