feat: Update Android build workflow to run on Linux and enhance sync cycle handling in ProtocolManager

.gitea/workflows/android.yaml

@@ -14,7 +14,7 @@ on:
 
 jobs:
   build:
-    runs-on: android-builders
+    runs-on: linux
     steps:
       - name: Checkout code
         uses: actions/checkout@v6

app/src/main/java/com/rosetta/messenger/network/ProtocolManager.kt

@@ -550,6 +550,13 @@ object ProtocolManager {
         subscribePushTokenIfAvailable()
     }
 
+    private fun finishSyncCycle(reason: String) {
+        addLog(reason)
+        setSyncInProgress(false)
+        retryWaitingMessages()
+        requestMissingUserInfo()
+    }
+
     /**
      * Send FCM push token to server (SUBSCRIBE).
      * Deduplicates: won't re-send the same token within one connection session.
@@ -689,6 +696,19 @@ object ProtocolManager {
                                 else -> 0L
                             }
 
+                    // Loop guard: if server keeps BATCH_END with unchanged cursor and we did not
+                    // process anything in this batch, treat sync as finished to avoid infinite loop.
+                    val noProgress =
+                            failuresInBatch == 0 &&
+                                    processedMaxTimestamp <= 0L &&
+                                    (nextCursor <= 0L || nextCursor == currentCursor)
+                    if (noProgress) {
+                        finishSyncCycle(
+                                "✅ SYNC COMPLETE — no progress on batch (server=$safeBatchTimestamp, current=$currentCursor)"
+                        )
+                        return@launch
+                    }
+
                     // If server batch timestamp runs ahead of what we actually processed, clamp it.
                     // This avoids skipping tail messages when packet delivery/parsing was partial.
                     if (processedMaxTimestamp > 0L && processedMaxTimestamp < safeBatchTimestamp) {
@@ -709,18 +729,11 @@ object ProtocolManager {
                 }
             }
             SyncStatus.NOT_NEEDED -> {
-                addLog("✅ SYNC COMPLETE — no more messages to sync")
                 // Synchronous — immediately marks sync as complete.
                 // Desktop parity: NOT_NEEDED just sets state to CONNECTED,
                 // does NOT update last_sync timestamp (unnecessary since client
                 // was already up to date).
-                setSyncInProgress(false)
-                // Retry any messages stuck in WAITING status from previous sessions.
-                retryWaitingMessages()
-                // Desktop parity: resolve names for all dialogs with empty titles.
-                // Desktop does this per-component via useUserInformation hook;
-                // we batch it after sync for efficiency.
-                requestMissingUserInfo()
+                finishSyncCycle("✅ SYNC COMPLETE — no more messages to sync")
             }
         }
     }