fix(android): wait for color grid to settle after horizontal swipe (#370)

After each successful horizontal swipe in color discovery, re-read the
color rows until two adjacent reads agree on text and bounds (at most four
extra reads, 200ms apart) before collecting. No extra clicks, never fails.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NTDbDcwbDw1TSAcE6wfh2F

android/app/src/main/java/cn/ilapage/goauto/agent/automation/PddProductDetailCollector.kt

@@ -1707,6 +1707,7 @@ class PddProductDetailCollector(
                         diagnosticHorizontalSwipes++
                         pause(350)
                         lastHorizontalSwipeDoneAt = now()
+                        settleColorGrid(goodsId, config, evidence)
                     }
                     trace("color-row-end row=$rowIndex end=$rowEnd skip=$rowSkipNote")
                     // An uncertain revisit cannot erase previously observed
@@ -1766,6 +1767,35 @@ class PddProductDetailCollector(
 
     private var lastHorizontalSwipeDoneAt = -1L
 
+    /**
+     * After a horizontal swipe the grid may still be coasting, so positions
+     * parsed now can differ from the ones at click time. Re-read the color rows
+     * until two adjacent reads agree (text + bounds), at most four more reads
+     * 200ms apart. Never fails the task and never clicks.
+     */
+    private fun settleColorGrid(goodsId: String, config: PddCollectorConfig, evidence: PageEvidence) {
+        val startedAt = now()
+        fun read(): List<String>? {
+            val screen = parse(goodsId, config, evidence)
+            if (screen.problem != null || !screen.pageEvidenceMatched) return null
+            return optionSignature(colorRows(screen).flatten())
+        }
+        var previous = read()
+        var reads = 0
+        var stable = false
+        while (previous != null && reads < 4) {
+            pause(200)
+            reads++
+            val current = read() ?: break
+            if (current == previous) {
+                stable = true
+                break
+            }
+            previous = current
+        }
+        trace("color-settle reads=$reads stable=$stable waitedMs=${now() - startedAt}")
+    }
+
     private fun traceColorClickMiss(screen: ParsedPddScreen, value: VisibleSpecValue, rows: List<List<VisibleSpecValue>>, result: FreshActionResult) {
         val rowIndex = rows.indexOfFirst { row -> row.any { it.text == value.text } }
         val column = rows.getOrNull(rowIndex).orEmpty().sortedBy { it.node.bounds.left }.indexOfFirst { it.text == value.text }

android/app/src/test/java/cn/ilapage/goauto/agent/PddProductDetailCollectorTest.kt

@@ -2217,6 +2217,47 @@ class PddProductDetailCollectorTest {
         assertTrue(payload.missing.isEmpty())
     }
 
+    private class SettleRun(val driver: FakeCollectorDriver, val result: PddCollectorResult, val traces: List<String>)
+
+    private fun inertiaGrid(inertia: Int): SettleRun {
+        val colors = gridColors(47)
+        val grid = listOf(colors.filterIndexed { i, _ -> i % 2 == 0 }, colors.filterIndexed { i, _ -> i % 2 == 1 })
+        val prices = colors.mapIndexed { i, c -> c to 1000L + i * 10L }.toMap()
+        val driver = FakeCollectorDriver(
+            colors = colors,
+            prices = prices,
+            horizontalGrid = grid,
+            gridPixelStep = 640,
+            gridInertiaCaptures = inertia,
+            gridStrictClickPosition = true,
+            sizePages = listOf(listOf("S"), listOf("M")),
+            hideColorHeadingAfterFirstVerticalPage = true,
+        )
+        var clock = 0L
+        val traces = mutableListOf<String>()
+        val result = PddProductDetailCollector(driver, { clock }, { clock += it }, trace = traces::add, taskId = 370)
+            .collect(GOODS_ID, rule(gridConfig()))
+        return SettleRun(driver, result, traces)
+    }
+
+    @Test
+    fun `color grid is settled after a horizontal swipe so coasting never misses a click`() {
+        val calm = inertiaGrid(inertia = 0)
+        val coasting = inertiaGrid(inertia = 2)
+
+        assertAll47Collected(coasting.result)
+        assertTrue(coasting.traces.none { it.startsWith("color-click-miss") })
+        // Waiting adds no clicks and never exceeds four extra reads.
+        assertEquals(calm.driver.clickCount, coasting.driver.clickCount)
+        val settles = coasting.traces.filter { it.startsWith("color-settle") }
+        assertTrue(settles.isNotEmpty())
+        settles.forEach { line ->
+            val reads = Regex("reads=([0-9]+)").find(line)!!.groupValues[1].toInt()
+            assertTrue(line, reads <= 4)
+        }
+        assertTrue(settles.any { it.contains("stable=true") })
+    }
+
     @Test
     fun `mid start with one anchor failure while resetting retries and still skips the reverse sweep`() {
         val (driver, result) = midStartGrid(failAttempts = setOf(2))
@@ -2408,6 +2449,12 @@ class PddProductDetailCollectorTest {
         private val gridInitialOffset: Int = 0,
         // #370: 1-based RIGHT swipe attempts that fail with anchorMissing.
         private val gridRightFailAttempts: Set<Int> = emptySet(),
+        // #370: after a horizontal swipe that moved the grid, the next N captures
+        // still show it coasting (nodes drift 30px per remaining capture).
+        private val gridInertiaCaptures: Int = 0,
+        // #370: a click is NOT_FOUND when the node is not where the last capture
+        // placed it (position at click time differs from the parsed target).
+        private val gridStrictClickPosition: Boolean = false,
     ) : PddCollectorDriver {
         var captureCount = 0
         var clickCount = 0
@@ -2420,6 +2467,8 @@ class PddProductDetailCollectorTest {
         val gridSwipeLog = mutableListOf<Pair<SwipeDirection, Int>>()
         private val gridOffsets = IntArray(horizontalGrid?.size ?: 0) { gridInitialOffset }
         private var rightAttempts = 0
+        private var inertiaRemaining = 0
+        private var currentDrift = 0
         private var lastSwipeFailure = "none"
         private var selected: String? = initialSelectedColor
         private var previousSelected: String? = null
@@ -2432,8 +2481,12 @@ class PddProductDetailCollectorTest {
         private var quickConfirmationRecovered = false
         private var adviceOpen = false
 
-        override fun capture(): UiSnapshot {
+        override fun capture(): UiSnapshot = captureFrame(advanceInertia = true)
+
+        private fun captureFrame(advanceInertia: Boolean): UiSnapshot {
             captureCount++
+            currentDrift = inertiaRemaining * 30
+            if (advanceInertia && inertiaRemaining > 0) inertiaRemaining--
             fixedSnapshot?.let { return it }
             if (adviceOpen) return UiSnapshot(PDD_PACKAGE, ACTIVITY, listOf(
                 node("content", "", 0, 0, 1080, 2200, resourceId = "android:id/content", className = "android.widget.FrameLayout"),
@@ -2516,7 +2569,7 @@ class PddProductDetailCollectorTest {
                     val path = "scroll/color-$color-$captureCount"
                     val shift = if (gridPixelStep != null) gridOffsets[row] else 0
                     val jitter = if (gridClickJitter && horizontalGrid != null) (clickCount % 4) * 2 else 0
-                    val left = 30 + column * 230 - shift + jitter
+                    val left = 30 + column * 230 - shift + jitter + currentDrift
                     val top = 470 + row * 90
                     if (imageColorCards) {
                         nodes += SnapshotNode(
@@ -2532,7 +2585,7 @@ class PddProductDetailCollectorTest {
                         )
                     } else {
                         nodes += node(
-                            path, color, left, top, 220 + column * 230 - shift + jitter, top + 70,
+                            path, color, left, top, 220 + column * 230 - shift + jitter + currentDrift, top + 70,
                             clickable = true, selected = displayedSelected() == color, parentPath = "scroll",
                         )
                     }
@@ -2592,9 +2645,10 @@ class PddProductDetailCollectorTest {
             clickCount++
             clickedLabels += target.label
             if (target.label in failedClicks) return FreshActionResult.FAILED
-            val current = capture().nodes.filter { it.label == target.label && (!imageColorCards || it.clickable) }
+            val current = captureFrame(advanceInertia = false).nodes.filter { it.label == target.label && (!imageColorCards || it.clickable) }
             if (current.isEmpty()) return FreshActionResult.NOT_FOUND
             if (current.size > 1) return FreshActionResult.AMBIGUOUS
+            if (gridStrictClickPosition && current.single().bounds != target.bounds) return FreshActionResult.NOT_FOUND
             if (!panelOpen && target.label == "单独购买") {
                 entryClickCount++
                 when {
@@ -2658,10 +2712,12 @@ class PddProductDetailCollectorTest {
                 }
                 val brokenSwipe = gridSwipeWhereOnlyFirstRowMoves > 0 &&
                     gridSwipeLog.size == gridSwipeWhereOnlyFirstRowMoves
+                val offsetsBefore = gridOffsets.toList()
                 moved.filter { !brokenSwipe || it == 0 }.forEach { r ->
                     val max = if (gridSharedContainer) sharedMax else horizontalGrid[r].size - gridVisibleColumns
                     gridOffsets[r] = (gridOffsets[r] + delta).coerceIn(0, maxOf(0, max))
                 }
+                if (gridOffsets.toList() != offsetsBefore) inertiaRemaining = gridInertiaCaptures
                 return true
             }
             if ((direction == SwipeDirection.UP || direction == SwipeDirection.DOWN) && !verticalSwipeSucceeds) return false