fix: correct bucketing and windowed ranges for chart rendering

Signed-off-by: Brandon McAnsh <git@bmcreations.dev>

Author: bmc08gt

apps/flipcash/features/tokens/src/main/kotlin/com/flipcash/app/tokens/internal/components/marketcap/MarketCapChart.kt

@@ -82,17 +82,23 @@ internal fun MarketCapChart(
         mutableStateOf<List<MarketCapPoint>>(emptyList())
     }
 
-    LaunchedEffect(data) {
+    // Track the period that corresponds to the current historicalData so we
+    // don't collapse stale data with a new period (which produces an
+    // intermediate curve that causes Vico to animate from the bottom).
+    var dataPeriod by remember { mutableStateOf(selectedPeriod) }
+
+    LaunchedEffect(data, selectedPeriod) {
         if (data.isNotEmpty()) {
             historicalData = data
+            dataPeriod = selectedPeriod
         }
     }
 
     val modelProducer = remember { CartesianChartModelProducer() }
 
-    val windowedData by remember(historicalData, selectedPeriod) {
+    val windowedData by remember(historicalData, dataPeriod) {
         derivedStateOf {
-            historicalData.collapse(selectedPeriod, currentValue = currentValue)
+            historicalData.collapse(dataPeriod, currentValue = currentValue)
         }
     }
 

apps/flipcash/shared/tokens/src/main/kotlin/com/flipcash/app/tokens/data/MarketCapPoint.kt

@@ -23,13 +23,8 @@ fun List<MarketCapPoint>.collapse(
         Period.All -> minOfOrNull { it.x } ?: now
     }
 
-    val filtered = filter { it.x >= startTime }.ifEmpty {
-        // No points fall within the period window — use the closest point
-        // so the chart still renders with targetPoints entries.
-        val nearest = minByOrNull { kotlin.math.abs(it.x - startTime) }
-            ?: return emptyList()
-        listOf(nearest)
-    }
+    val filtered = filter { it.x >= startTime }
+    if (filtered.isEmpty()) return emptyList()
 
     val duration = now - startTime
     val intervalMs = (duration / targetPoints).coerceAtLeast(1)