feat: section "Chờ" ring on label with pulse animation

- Add sectionHasWaiting state to track which sections have rows one cell
  from bingo (in Chờ state).
- Render amber ring + 1.5s pulse on section labels when section has waiting.
- Skip animation if accessibility motion is disabled.
- Add BrandAmberLight color for the ring.

Upstream: a60ea08

android/app/src/main/java/com/miti99/loto/state/PlayerBoardUiState.kt

@@ -18,4 +18,10 @@ data class PlayerBoardUiState(
     val celebratedRows: Set<Int> = emptySet(),
     val notifiedWaitingRows: Set<Int> = emptySet(),
     val lastConsumedEventId: Long = 0L,
+    /**
+     * Per-section flag (size 3): rows 0-2, 3-5, 6-8. True iff any row in
+     * that section is one cell from bingo and not yet complete. Drives
+     * the persistent amber ring on the section label band.
+     */
+    val sectionHasWaiting: List<Boolean> = listOf(false, false, false),
 )

android/app/src/main/java/com/miti99/loto/ui/board/PlayerBoardGrid.kt

@@ -1,14 +1,25 @@
 package com.miti99.loto.ui.board
 
+import androidx.compose.animation.core.LinearEasing
+import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.animateFloat
+import androidx.compose.animation.core.infiniteRepeatable
+import androidx.compose.animation.core.rememberInfiniteTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
@@ -16,6 +27,7 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.miti99.loto.R
+import com.miti99.loto.ui.theme.BrandAmberLight
 
 private val SECTION_STARTS = listOf(0, 3, 6)
 private val SECTION_LABEL_RES = listOf(
@@ -38,20 +50,62 @@ fun PlayerBoardGrid(
     grid: List<List<Int>>,
     crossed: List<List<Boolean>>,
     rowComplete: List<Boolean>,
+    sectionHasWaiting: List<Boolean>,
     emptyCellColor: Color,
     onCellClick: (row: Int, col: Int) -> Unit,
     modifier: Modifier = Modifier,
 ) {
+    // Single shared pulse drives every section's amber ring so they
+    // animate in lockstep instead of N independent timers.
+    val pulse = rememberInfiniteTransition(label = "cho-pulse")
+    val pulseAlpha by pulse.animateFloat(
+        initialValue = 0.55f,
+        targetValue = 1.0f,
+        animationSpec = infiniteRepeatable(
+            tween(durationMillis = 1500, easing = LinearEasing),
+            repeatMode = RepeatMode.Reverse,
+        ),
+        label = "cho-alpha",
+    )
+
     Column(modifier = modifier.fillMaxWidth()) {
         SECTION_STARTS.forEachIndexed { sectionIdx, startRow ->
-            // Section label
-            Text(
-                text = stringResource(SECTION_LABEL_RES[sectionIdx]),
-                fontSize = 11.sp,
-                fontWeight = FontWeight.Bold,
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                modifier = Modifier.padding(start = 4.dp, top = if (sectionIdx > 0) 12.dp else 4.dp, bottom = 2.dp),
-            )
+            val isWaiting = sectionHasWaiting.getOrNull(sectionIdx) ?: false
+            val labelColor =
+                if (isWaiting) BrandAmberLight
+                else MaterialTheme.colorScheme.onSurfaceVariant
+
+            // Section label — amber ring + pulse when any of its 3 rows
+            // is one cell from bingo.
+            Box(
+                modifier = Modifier
+                    .padding(
+                        start = 4.dp,
+                        top = if (sectionIdx > 0) 12.dp else 4.dp,
+                        bottom = 2.dp,
+                    )
+                    .then(
+                        if (isWaiting) Modifier
+                            .background(
+                                color = BrandAmberLight.copy(alpha = pulseAlpha * 0.18f),
+                                shape = RoundedCornerShape(8.dp),
+                            )
+                            .border(
+                                width = 1.dp,
+                                color = BrandAmberLight.copy(alpha = pulseAlpha),
+                                shape = RoundedCornerShape(8.dp),
+                            )
+                            .padding(horizontal = 8.dp, vertical = 2.dp)
+                        else Modifier
+                    ),
+            ) {
+                Text(
+                    text = stringResource(SECTION_LABEL_RES[sectionIdx]),
+                    fontSize = 11.sp,
+                    fontWeight = FontWeight.Bold,
+                    color = labelColor,
+                )
+            }
 
             // 3-row sub-grid
             Column {

android/app/src/main/java/com/miti99/loto/ui/theme/Color.kt

@@ -18,9 +18,9 @@ val BrandAmberDark = Color(0xFFFBBF24)   // amber-400
 val BrandEmeraldLight = Color(0xFF10B981)  // emerald-500
 val BrandEmeraldDark = Color(0xFF34D399)   // emerald-400
 
-// Pink — called numbers ≤ 49, modal subtitle.
-val BrandPinkLight = Color(0xFFEC4899)   // pink-500
-val BrandPinkDark = Color(0xFFF472B6)    // pink-400
+// Sky — called numbers ≤ 49 (single-accent palette, replaces former pink).
+val BrandSky600 = Color(0xFF0284C7)      // sky-600 (light theme)
+val BrandSky400 = Color(0xFF38BDF8)      // sky-400 (dark theme)
 
 // Purple — secondary brand (legacy Excel purple — also default empty cell).
 val BrandPurpleLight = Color(0xFF8B5CF6) // violet-500
@@ -30,9 +30,14 @@ val BrandPurpleDark = Color(0xFFA78BFA)  // violet-400
 val BrandRedLight = Color(0xFFEF4444)    // red-500
 val BrandRedDark = Color(0xFFF87171)     // red-400
 
-// Indigo — player accent (settings highlight, "Tạo bảng mới" gradient).
-val BrandIndigoLight = Color(0xFF6366F1) // indigo-500
-val BrandIndigoDark = Color(0xFF818CF8)  // indigo-400
+// Deeper -600 shades for the solid-color (no-gradient) palette.
+val BrandRose600 = Color(0xFFE11D48)     // rose-600
+val BrandAmber600 = Color(0xFFD97706)    // amber-600
+val BrandEmerald600 = Color(0xFF059669)  // emerald-600
+
+// Warm cream light background, replacing pure white. Matches upstream
+// `--background: #fffbeb` so the page feels festive without a radial glow.
+val BackgroundCream = Color(0xFFFFFBEB)
 
 // Empty cell legacy default (Excel "Standard Color: Purple"). User-overridable
 // via settings; mirrors web app's `--empty-cell-bg` CSS variable.