fix: deck picker subtitle ignores 9999 cap

AnkiDroid/src/main/java/com/ichi2/anki/deckpicker/DeckPickerViewModel.kt

@@ -56,6 +56,7 @@ import com.ichi2.anki.reviewreminders.ScheduleRemindersDestination
 import com.ichi2.anki.settings.Prefs
 import com.ichi2.anki.syncAuth
 import com.ichi2.anki.utils.Destination
+import com.ichi2.anki.utils.ext.allDecksCountsUncapped
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableSharedFlow
@@ -166,10 +167,14 @@ class DeckPickerViewModel :
             tree.onlyHasDefaultDeck() && noCards
         }.stateIn(viewModelScope, SharingStarted.Eagerly, initialValue = null)
 
+    // The deck-tree protobuf clamps each node's new/review/learn counts at 9999
+    // (backend behavior, shared with Anki Desktop), so summing the root's three
+    // fields underreports for large collections — see issue #17605. Route through
+    // `allDecksCountsUncapped` (uncapped, limit-aware via getQueuedCards) instead.
     val flowOfCardsDue =
         combine(flowOfDeckDueTree, flowOfDeckListInInitialState) { tree, inInitialState ->
             if (tree == null || inInitialState != false) return@combine null
-            tree.newCount + tree.revCount + tree.lrnCount
+            withCol { sched.allDecksCountsUncapped().count() }
         }
 
     /** "Studied N cards in 0 seconds today */

AnkiDroid/src/main/java/com/ichi2/anki/utils/ext/Scheduler.kt

@@ -45,3 +45,30 @@ fun Scheduler.allDecksCounts(): Counts {
     }
     return total
 }
+
+/**
+ * Like [allDecksCounts] but uncapped: per-node counts on the deck-tree protobuf
+ * are clamped at 9999 by the backend, so summing them produces a wrong total
+ * for large collections (issue #17605). This iterates top-level decks and pulls
+ * each subtree's count from [Scheduler.counts] instead, which sources from
+ * `getQueuedCards` and is both limit-aware and unclamped — the same source
+ * `StudyOptionsFragment` uses to display per-deck counts.
+ *
+ * Side effect: temporarily mutates and restores `decks.selected()`.
+ */
+fun Scheduler.allDecksCountsUncapped(): Counts {
+    val total = Counts()
+    val previouslySelected = col.decks.selected()
+    try {
+        for (node in deckDueTree().children) {
+            col.decks.select(node.did)
+            val c = counts()
+            total.addNew(c.new)
+            total.addLrn(c.lrn)
+            total.addRev(c.rev)
+        }
+    } finally {
+        col.decks.select(previouslySelected)
+    }
+    return total
+}