Avoid showing the same verb back-to-back in practice

fetchDueCard now accepts the last-shown verb ID and prefers a
different verb from the due queue. Falls back to the same verb
only when it's the sole due card.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Conjuga/Conjuga/Services/PracticeSessionService.swift

@@ -48,7 +48,7 @@ struct PracticeSessionService {
         PracticeSettings(progress: ReviewStore.fetchOrCreateUserProgress(context: cloudContext))
     }
 
-    func nextCard(for focusMode: FocusMode) -> PracticeCardLoad? {
+    func nextCard(for focusMode: FocusMode, excludingVerbId lastVerbId: Int? = nil) -> PracticeCardLoad? {
         switch focusMode {
         case .weakVerbs:
             if let form = pickWeakForm() {
@@ -62,7 +62,7 @@ struct PracticeSessionService {
             break
         }
 
-        if let dueCard = fetchDueCard() {
+        if let dueCard = fetchDueCard(excluding: lastVerbId) {
             return loadCard(from: dueCard)
         }
 
@@ -146,7 +146,7 @@ struct PracticeSessionService {
         )
     }
 
-    private func fetchDueCard() -> ReviewCard? {
+    private func fetchDueCard(excluding lastVerbId: Int?) -> ReviewCard? {
         let settings = settings()
         let allowedVerbIds = referenceStore.allowedVerbIDs(selectedLevel: settings.selectedLevel)
         let now = Date()
@@ -157,11 +157,20 @@ struct PracticeSessionService {
         descriptor.fetchLimit = settings.enabledTenses.isEmpty ? 10 : 50
         let cards = (try? cloudContext.fetch(descriptor)) ?? []
 
-        return cards.first { card in
+        let eligible = cards.filter { card in
             allowedVerbIds.contains(card.verbId) &&
             (settings.enabledTenses.isEmpty || settings.enabledTenses.contains(card.tenseId)) &&
             (settings.showVosotros || card.personIndex != 4)
         }
+
+        // Prefer a card from a different verb than the last one shown.
+        // Fall back to the same verb only if it's the sole due card.
+        if let lastVerbId {
+            if let different = eligible.first(where: { $0.verbId != lastVerbId }) {
+                return different
+            }
+        }
+        return eligible.first
     }
 
     private func pickWeakForm() -> VerbForm? {

Conjuga/Conjuga/ViewModels/PracticeViewModel.swift

@@ -96,7 +96,7 @@ final class PracticeViewModel {
         hasCards = true
         isLoading = true
         let service = PracticeSessionService(localContext: localContext, cloudContext: cloudContext)
-        guard let cardLoad = service.nextCard(for: focusMode) else {
+        guard let cardLoad = service.nextCard(for: focusMode, excludingVerbId: currentVerb?.id) else {
             clearCurrentCard()
             hasCards = false
             isLoading = false