Fix widget wiping the Books tables on every refresh

The widget extension opened the shared local SwiftData store with a
7-entity schema while the app's store has 10. SwiftData treats the
smaller schema as a migration and destructively drops the unlisted
tables — so every widget refresh deleted the bundled Book/BookChapter
rows (and DownloadedVideo), which is why books vanished after reinstalls.

Introduce SharedStore.localSchemaModels as the single source of truth
for the local schema and build the app and both widget containers from
it, so app and widget can no longer drift apart. The same class of bug
hit TextbookChapter previously; a shared list prevents a third recurrence.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Conjuga/ConjugaWidget/CombinedWidget.swift

@@ -41,24 +41,19 @@ struct CombinedProvider: TimelineProvider {
     private func fetchWordOfDay(for date: Date) -> WordOfDay? {
         guard let localURL = SharedStore.localStoreURL() else { return nil }
 
-        // MUST declare all 7 local entities to match the main app's schema.
-        // Declaring a subset would cause SwiftData to destructively migrate the
-        // store on open, dropping the entities not listed here (this is how we
-        // previously lost all TextbookChapter rows on every widget refresh).
+        // Open the store with the SAME schema as the main app. A subset schema
+        // would make SwiftData destructively migrate the store on open and drop
+        // every unlisted table (this is how widget refreshes kept wiping the
+        // bundled Book rows, and TextbookChapter before them).
+        let schema = Schema(SharedStore.localSchemaModels)
         let config = ModelConfiguration(
             "local",
-            schema: Schema([
-                Verb.self, VerbForm.self, IrregularSpan.self,
-                TenseGuide.self, CourseDeck.self, VocabCard.self,
-                TextbookChapter.self,
-            ]),
+            schema: schema,
             url: localURL,
             cloudKitDatabase: .none
         )
         guard let container = try? ModelContainer(
-            for: Verb.self, VerbForm.self, IrregularSpan.self,
-                 TenseGuide.self, CourseDeck.self, VocabCard.self,
-                 TextbookChapter.self,
+            for: schema,
             configurations: config
         ) else { return nil }