feat: increase background stop debounce time

app/src/main/java/to/bitkit/repositories/LightningRepo.kt

@@ -585,6 +585,17 @@ class LightningRepo @Inject constructor(
      * Scheduling and cancelling are atomic: [cancelPendingStop] runs on the repo dispatcher while this
      * runs on the caller thread, so an interleaved cancel could otherwise miss the job being installed
      * and stop the node after the app is back in the foreground.
+     *
+     * [BACKGROUND_STOP_DELAY] must stay under the cached-app freezer debounce (~10s once the process
+     * drops to `oom_adj` 900) so [stop] is at least entered before the process can be frozen. Past
+     * that the process freezes mid-delay and the stop only fires on unfreeze, racing
+     * [cancelPendingStop] to tear the node down just as the user returns — and [stop] runs
+     * `NonCancellable`, so losing that race is unrecoverable.
+     *
+     * Whether the stop *completes* in that window is out of scope here: on a wallet with real
+     * payment history ldk_node reliably hits its own 30s event-handling deadline, so no delay value
+     * makes the teardown fit. That also makes an avoided teardown valuable, since a user returning
+     * mid-stop waits it out before the ~8s node rebuild can start.
      */
     fun stopDebounced() = synchronized(pendingStopLock) {
         val job = scope.launch {
@@ -1896,7 +1907,7 @@ class LightningRepo @Inject constructor(
         private const val VSS_KEY_EXTERNAL_SCORES_CACHE = "external_pathfinding_scores_cache"
         private const val MS_SYNC_LOOP_DEBOUNCE = 500L
         private const val SYNC_RETRY_DELAY_MS = 15_000L
-        private val BACKGROUND_STOP_DELAY = 3.seconds
+        private val BACKGROUND_STOP_DELAY = 5.seconds
         private val CHANNELS_USABLE_TIMEOUT = 15.seconds
         private val NO_USABLE_CHANNELS_FEEDBACK_DELAY = 2_500.milliseconds
         val SEND_LN_TIMEOUT = 10.seconds

app/src/test/java/to/bitkit/repositories/LightningRepoTest.kt

@@ -88,7 +88,7 @@ import kotlin.time.Duration.Companion.seconds
 class LightningRepoTest : BaseUnitTest() {
     companion object {
         private const val NO_USABLE_CHANNELS_FEEDBACK_DELAY_MS = 2_500L
-        private const val BACKGROUND_STOP_DELAY_MS = 3_000L
+        private const val BACKGROUND_STOP_DELAY_MS = 5_000L
     }
 
     private lateinit var sut: LightningRepo

changelog.d/next/1146.changed.md

@@ -0,0 +1 @@
+Bitkit now keeps the Lightning node running a little longer when you briefly leave the app, so quick trips to another app no longer reload the wallet on return.