fix(download): don't show the update card for current dictionaries

areDictionariesUpToDate() mapped every exception to NeedsUpdate, and
the post-update recheck ran after the first indexed source of a batch,
before later sources finished downloading; the interim NeedsUpdate
persisted for the day. Treat unexpected errors as up to date, rethrow
cancellation, and recheck once when the download batch completes.

app/src/main/java/com/example/research/feature/download/repository/DictionaryChecker.kt

@@ -7,6 +7,7 @@ import com.example.research.common.util.FileStorageManager
 import com.example.research.common.util.DocumentFileInfo
 import com.example.research.core.domain.model.DictionarySource
 import com.example.research.feature.download.config.DictionaryConfig
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
@@ -101,9 +102,11 @@ class DictionaryChecker(
             }
 
             return@withContext !serverCanOfferNewer
+        } catch (e: CancellationException) {
+            throw e
         } catch (e: Exception) {
             Log.e(TAG, "Error checking currency: ${e.message}", e)
-            false
+            true
         }
     }
 

app/src/main/java/com/example/research/ui/settings/SettingsViewModel.kt

@@ -133,8 +133,6 @@ class SettingsViewModel(
 
     private fun setupStateObservation() {
         viewModelScope.launch {
-            var wasIndexing = false
-
             val dictionaryStateInputs = combine(
                 preferencesManager.themeMode.map { mode ->
                     try { AppTheme.valueOf(mode) } catch (_: Exception) { AppTheme.SYSTEM }
@@ -174,18 +172,7 @@ class SettingsViewModel(
             }
 
             combine(dictionaryStateInputs, operationStateInputs) { dictionaryState, operationState ->
-                // Handle indexing completion side effect
                 val isIndexing = dictionaryState.indexingProgress.isIndexing
-                if (wasIndexing && !isIndexing) {
-                    if (isDownloadInProgress) {
-                        isDownloadInProgress = false
-                        dictionaryStatus.value = withContext(Dispatchers.IO) {
-                            evaluateDictionaryStatus()
-                        }
-                    }
-                }
-                wasIndexing = isIndexing
-
                 when (operationState.downloadState) {
                     is DownloadState.Loading, is DownloadState.Extracting -> {
                         isDownloadInProgress = true
@@ -194,6 +181,10 @@ class SettingsViewModel(
                     }
                     is DownloadState.Success -> {
                         pendingSourceUrls.clear()
+                        isDownloadInProgress = false
+                        dictionaryStatus.value = withContext(Dispatchers.IO) {
+                            evaluateDictionaryStatus()
+                        }
                     }
                     is DownloadState.Error -> {
                         isDownloadInProgress = false