fix(sync): IMPL_08B - Bypass global cooldown for onSave syncs

Changes:
- Constants.kt: Add SYNC_ONSAVE_TAG constant for worker tagging
- NoteEditorViewModel.triggerOnSaveSync(): Tag SyncWorker with "onsave" tag
- SyncWorker.doWork(): Skip global cooldown check for onSave-tagged workers
- onSave retains 3 protection layers: 5s own throttle, tryStartSync mutex, syncMutex
- Auto/WiFi/periodic syncs still respect 30s global cooldown

android/app/src/main/java/dev/dettmer/simplenotes/sync/SyncWorker.kt

@@ -111,8 +111,13 @@ class SyncWorker(
             // Verhindert dass Foreground und Background gleichzeitig syncing-State haben
             val prefs = applicationContext.getSharedPreferences(Constants.PREFS_NAME, Context.MODE_PRIVATE)
             
-            // Globaler Cooldown-Check (verhindert unnötige Server-Checks)
+            // 🆕 v1.8.1 (IMPL_08B): onSave-Syncs bypassen den globalen Cooldown
-            if (!SyncStateManager.canSyncGlobally(prefs)) {
+            // Grund: User hat explizit gespeichert → erwartet zeitnahen Sync
+            // Der eigene 5s-Throttle + isSyncing-Mutex reichen als Schutz
+            val isOnSaveSync = tags.contains(Constants.SYNC_ONSAVE_TAG)
+            
+            // Globaler Cooldown-Check (nicht für onSave-Syncs)
+            if (!isOnSaveSync && !SyncStateManager.canSyncGlobally(prefs)) {
                 Logger.d(TAG, "⏭️ SyncWorker: Global sync cooldown active - skipping")
                 if (BuildConfig.DEBUG) {
                     Logger.d(TAG, "✅ SyncWorker.doWork() SUCCESS (cooldown)")

android/app/src/main/java/dev/dettmer/simplenotes/ui/editor/NoteEditorViewModel.kt

@@ -545,6 +545,7 @@ class NoteEditorViewModel(
         Logger.d(TAG, "📤 Triggering onSave sync")
         val syncRequest = OneTimeWorkRequestBuilder<SyncWorker>()
             .addTag(Constants.SYNC_WORK_TAG)
+            .addTag(Constants.SYNC_ONSAVE_TAG)  // 🆕 v1.8.1 (IMPL_08B): Bypassed globalen Cooldown
             .build()
         WorkManager.getInstance(getApplication()).enqueue(syncRequest)
     }

android/app/src/main/java/dev/dettmer/simplenotes/utils/Constants.kt

@@ -86,4 +86,7 @@ object Constants {
     // 🆕 v1.8.1 (IMPL_08): Globaler Sync-Cooldown (über alle Trigger hinweg)
     const val KEY_LAST_GLOBAL_SYNC_TIME = "last_global_sync_timestamp"
     const val MIN_GLOBAL_SYNC_INTERVAL_MS = 30_000L  // 30 Sekunden
+    
+    // 🆕 v1.8.1 (IMPL_08B): onSave-Sync Worker-Tag (bypassed globalen Cooldown)
+    const val SYNC_ONSAVE_TAG = "onsave"
 }