sessions: make the launch display authoritative and finish the foreground policy

startSession re-derived the emulator display from the global roles-swapped
flag with a hardcoded DEFAULT_DISPLAY+1, clobbering the per-game display
target handleDualPlay had already resolved, so cross-display sessions got
tracked as same-display and killed by resume cleanup with their input never
forwarded. The launch path write is now authoritative and startSession only
falls back through assignEmulatorDisplayForSessionStart, which routes via
DisplayAffinityHelper for the real secondary display id.

SecondaryHomeActivity.onResume drops the 15s isPackageInForeground poll for
the display rule mirrored from MainActivity: the companion surfacing on the
display the emulator owned means the game left it and the session is over.
Both activities enforce the same invariant on their own display. The
immediate-end policy is scoped to dual-screen devices; single screen keeps
the 15s grace in cleanupStaleSession so quick hop-out-and-back relaunches
still resume the running emulator.

onForegroundChanged reads in-memory hasLiveSession instead of the session
prefs flag that races the async session-start write and lags save sync.
onTaskRemoved treats a null DSM holder as no live session, a persisted
session across a process restart is an orphan and must not block the
bottom-screen release.

Author: tmgast

app/src/main/kotlin/com/nendo/argosy/DualScreenManager.kt

@@ -2225,6 +2225,12 @@ class DualScreenManager(
         emulatorDisplayId = displayId
     }
 
+    /** Fallback for launch paths that never assigned a display; the launch path's write wins. */
+    fun assignEmulatorDisplayForSessionStart() {
+        if (emulatorDisplayId != null) return
+        emulatorDisplayId = displayAffinityHelper.getEmulatorDisplayId(_isRolesSwapped.value)
+    }
+
     fun startStartupGuard() {
         startupGuardJob?.cancel()
         startupGuardJob = scope.launch {

app/src/main/kotlin/com/nendo/argosy/MainActivity.kt

@@ -85,6 +85,7 @@ class MainActivity : ComponentActivity() {
     @Inject lateinit var ambientLedManager: AmbientLedManager
     @Inject lateinit var screenCaptureManager: ScreenCaptureManager
     @Inject lateinit var displayAffinityHelper: DisplayAffinityHelper
+    @Inject lateinit var permissionHelper: com.nendo.argosy.util.PermissionHelper
     @Inject lateinit var gameActionsDelegate: GameActionsDelegate
     @Inject lateinit var gameLaunchDelegate: GameLaunchDelegate
     @Inject lateinit var saveCacheManager: SaveCacheManager
@@ -620,10 +621,12 @@ class MainActivity : ComponentActivity() {
     }
 
     /**
-     * The launcher UI returning to the foreground means the session on this display
-     * is over: end it and restore the companion immediately. Only a session running
-     * on a different display (swapped roles / per-game display target) survives,
-     * since the game and the launcher UI legitimately coexist there.
+     * On dual-screen devices the launcher UI returning to the foreground means the
+     * session on this display is over: end it and restore the companion immediately.
+     * Only a session on a different display (swapped roles / per-game display target)
+     * survives, since the game and the launcher UI legitimately coexist there.
+     * Single-screen devices keep the resume-friendly grace: a session whose emulator
+     * was foregrounded within the last 15s stays alive so relaunching resumes it.
      */
     private fun cleanupStaleSession() {
         activityScope.launch {
@@ -632,6 +635,12 @@ class MainActivity : ComponentActivity() {
             val emulatorDisplay = dualScreenManager.emulatorDisplayId
             val ownDisplay = window.decorView.display?.displayId
             if (emulatorDisplay != null && ownDisplay != null && emulatorDisplay != ownDisplay) return@launch
+            if (!displayAffinityHelper.hasSecondaryDisplay && emulatorDisplay != null) {
+                val emulatorPkg = sessionStateStore.getEmulatorPackage()
+                if (emulatorPkg != null &&
+                    permissionHelper.isPackageInForeground(this@MainActivity, emulatorPkg, 15_000)
+                ) return@launch
+            }
             if (playSessionTracker.activeSession.value == null &&
                 preferencesRepository.getPersistedSession() == null
             ) return@launch

app/src/main/kotlin/com/nendo/argosy/data/emulator/PlaySessionTracker.kt

@@ -448,12 +448,7 @@ class PlaySessionTracker @Inject constructor(
                 variantFileId = variantFileId
             )
 
-            val displayId = if (sessionStateStore.isRolesSwapped()) {
-                android.view.Display.DEFAULT_DISPLAY + 1
-            } else {
-                android.view.Display.DEFAULT_DISPLAY
-            }
-            DualScreenManagerHolder.instance?.setEmulatorDisplay(displayId)
+            DualScreenManagerHolder.instance?.assignEmulatorDisplayForSessionStart()
 
             broadcastSessionChanged(gameId, channelName, isHardcore)
 

app/src/main/kotlin/com/nendo/argosy/hardware/CompanionGuardService.kt

@@ -15,7 +15,6 @@ import androidx.core.app.NotificationCompat
 import com.nendo.argosy.DualScreenManagerHolder
 import com.nendo.argosy.MainActivity
 import com.nendo.argosy.R
-import com.nendo.argosy.data.preferences.SessionStateStore
 import com.nendo.argosy.util.SecondaryHomeComponent
 
 class CompanionGuardService : Service() {
@@ -69,8 +68,7 @@ class CompanionGuardService : Service() {
         if (rootIntent?.component?.className != MainActivity::class.java.name) return
         if (SecondaryHomeComponent.isDefaultHome(this)) return
         val dsm = DualScreenManagerHolder.instance
-        val sessionLive = dsm?.hasLiveSession()
-            ?: SessionStateStore(applicationContext).hasActiveSession()
+        val sessionLive = dsm?.hasLiveSession() == true
         if (sessionLive) return
         Log.i(TAG, "Main task removed while not default home, releasing secondary display")
         SecondaryHomeComponent.setEnabled(this, false)

app/src/main/kotlin/com/nendo/argosy/hardware/SecondaryHomeActivity.kt

@@ -287,16 +287,14 @@ class SecondaryHomeActivity :
         isSaveDirty = store.isSaveDirty()
         broadcasts.broadcastCompanionResumed()
 
-        if (isGameActive && dsm.emulatorDisplayId != null && !dsm.isLaunchingGame) {
-            val emulatorPkg = dsm.sessionStateStore.getEmulatorPackage()
-            if (emulatorPkg != null) {
-                val helper = com.nendo.argosy.util.PermissionHelper()
-                if (!helper.isPackageInForeground(this, emulatorPkg, withinMs = 15_000)) {
-                    android.util.Log.d("SecondaryHome", "Emulator exited on secondary display, ending session")
-                    dsm.emulatorDisplayId = null
-                    dsm.playSessionTracker.endSessionInBackground()
-                    dsm.broadcastSessionCleared()
-                }
+        if (isGameActive && !dsm.isLaunchingGame) {
+            val emulatorDisplay = dsm.emulatorDisplayId
+            val ownDisplay = window.decorView.display?.displayId
+            if (emulatorDisplay != null && ownDisplay != null && emulatorDisplay == ownDisplay) {
+                android.util.Log.d("SecondaryHome", "Companion resumed on the emulator's display, ending session")
+                dsm.emulatorDisplayId = null
+                dsm.playSessionTracker.endSessionInBackground()
+                dsm.broadcastSessionCleared()
             }
         }
     }
@@ -384,7 +382,7 @@ class SecondaryHomeActivity :
         isArgosyForeground = isForeground
         if (isForeground && isGameActive) {
             val outOfGame = if (isShowcaseRole) {
-                !dsm.sessionStateStore.hasActiveSession()
+                !dsm.hasLiveSession()
             } else {
                 true
             }