Use ball first-hit rays and retry native prop-occluded split selections through normal merge

tools/android/exercise-final-progression.ps1

@@ -24,6 +24,14 @@ function ZoomOut([int]$Stage,$CurrentBoard) {
     Check "stage-$Stage-pinch-preserves-board" ((Same $CurrentBoard.balls $after.balls)-and(Same $CurrentBoard.groups $after.groups)-and(Same $CurrentBoard.countedBallIds $after.countedBallIds)-and$after.camera.distance-gt$CurrentBoard.camera.distance) 'Actual two-finger zoom-out; no ball, membership or count edits'
     return $after
 }
+function RevealBall([int]$Stage,[string]$Id,[string]$Name) {
+    for($view=0;$view-lt12;$view++){
+        $board=Board (Save "$Name-view-$view") $Stage
+        if(BallClear $board $Id){return $board}
+        Orbit "$Name-orbit-$view" $board
+    }
+    throw "No safe first-hit view for actual ball $Id within a full native orbit."
+}
 function MergeReal([int]$Stage,[string]$Name) {
     for($attempt=0;$attempt-lt16;$attempt++) {
         $before=Save "$Name-before-$attempt"; $board=Board $before $Stage
@@ -35,8 +43,9 @@ function MergeReal([int]$Stage,[string]$Name) {
             $delta=[Numerics.Vector3]::Transform([Numerics.Vector3]::new($s.x-$t.x,$s.y-$t.y,$s.z-$t.z),[Numerics.Quaternion]::Inverse($rotation))
             [pscustomobject]@{sid=$sid;tid=$tid;depth=[Math]::Abs($delta.Z);size=$source.ballIds.Count}
         }}}}) | Sort-Object depth,size
-        $pair=$pairs[0]
-        if($pair.depth-lt.9) {
+        $pair=$null
+        foreach($candidate in $pairs){if($candidate.depth-lt.9-and(BallClear $board $candidate.sid)){$pair=$candidate;break}}
+        if($pair) {
             $start=BallPoint $board $pair.sid; $end=BallPoint $board $pair.tid
             # Try a short lateral contact offset, then orbit to expose another depth plane if blocked.
             $offset=if($attempt%2-eq0){-35}else{35}
@@ -53,15 +62,22 @@ function SplitReal([int]$Stage,[int]$Selected,[string]$Name) {
         $before=Save "$Name-before-$attempt"; $board=Board $before $Stage
         $group=@($board.groups|Sort-Object {$_.ballIds.Count} -Descending)[0]
         $ids=@(if($Stage-eq13-and$Selected-eq2){$group.ballIds[0];$group.ballIds[-1]}else{$group.ballIds|Select-Object -First $Selected})
-        if(@($ids|Where-Object{!(BallClear $board $_)}).Count){Orbit "$Name-reveal-selected-$attempt" $board;continue}
+        $board=RevealBall $Stage $ids[0] "$Name-choose-reveal-$attempt"
         TapBall "$Name-choose-$attempt" $board $ids[0]
         Step "$Name-mode-$attempt" @('shell','input','tap','312','832')
-        foreach($id in $ids){TapBall "$Name-select-$attempt-$id" $board $id}
+        foreach($id in $ids){$board=RevealBall $Stage $id "$Name-select-reveal-$attempt-$id";TapBall "$Name-select-$attempt-$id" $board $id}
+        $board=RevealBall $Stage $ids[0] "$Name-drag-reveal-$attempt"
         $point=BallPoint $board $ids[0]
         Step "$Name-drag-$attempt" @('shell','input','swipe',"$($point[0])","$($point[1])","$($point[0])","$($point[1]-160)",'500')
         $after=Save "$Name-after-$attempt"; $actual=Board $after $Stage
         if($null-eq$actual){$actual=$after.latestFreePlay}
         if($actual.groups.Count-gt$board.groups.Count){
+            if(@($actual.groups|Where-Object{(($_.ballIds|Sort-Object)-join',')-eq(($ids|Sort-Object)-join',')}).Count-ne1){
+                $commands.Add(@{command='Actual split selected IDs differ: preserve attempt and retry through native merge/orbit';expected=$ids;actualGroups=$actual.groups;utc=[DateTime]::UtcNow.ToString('o')})
+                MergeReal $Stage "$Name-remerge-$attempt"|Out-Null
+                Orbit "$Name-retry-view-$attempt" (Board (Save "$Name-retry-state-$attempt") $Stage)
+                continue
+            }
             Check "$Name-exact-selected-ids-$attempt" (@($actual.groups|Where-Object{(($_.ballIds|Sort-Object)-join',')-eq(($ids|Sort-Object)-join',')}).Count-eq1) 'Native split group is exactly the tapped selection, not an occluded substitute'
             return $after
         }
@@ -98,7 +114,7 @@ function CountRemaining([int]$Stage) {
         $uncounted=@($board.balls|Where-Object {$board.countedBallIds-notcontains$_.id})
         $beforeCount=$board.countedBallIds.Count
         $id=$null
-        foreach($ball in $uncounted){if(WorldSafe (BallPoint $board $ball.id)){$id=$ball.id;break}}
+        foreach($ball in $uncounted){if(BallClear $board $ball.id){$id=$ball.id;break}}
         if(!$id){Orbit "stage-$Stage-count-safe-view-$attempt" $board;continue}
         TapBall "stage-$Stage-count-$attempt" $board $id
         $after=Save "stage-$Stage-count-$attempt-after"; $newBoard=Board $after $Stage