Add word-book practice, iOS app shell, and fix embedded WebView blank screen.

Ship dual-track learning (daily accumulation vs textbook),沪教/商务词书 APIs and UI, native iOS wrapper with bundled H5, and production book import on deploy.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/services/memory_visual_service.py

@@ -57,14 +57,23 @@ def mastery_at_time(word: Word, records: list[QuizRecord], at: datetime) -> floa
 
 
 class MemoryVisualService:
-    def get_visualization(self, db: Session, user: User, horizon_days: int = 30) -> dict:
-        words = db.query(Word).filter(Word.user_id == user.id).all()
-        records = (
-            db.query(QuizRecord)
+    def get_visualization(
+        self, db: Session, user: User, horizon_days: int = 30, book_id: int = 0
+    ) -> dict:
+        words = (
+            db.query(Word)
+            .filter(Word.user_id == user.id, Word.book_id == book_id, Word.status != "locked")
+            .all()
+        )
+        word_ids = {w.id for w in words}
+        records = [
+            r
+            for r in db.query(QuizRecord)
             .filter(QuizRecord.user_id == user.id)
             .order_by(QuizRecord.created_at.asc())
             .all()
-        )
+            if r.word_id in word_ids
+        ]
         records_by_word: dict[int, list[QuizRecord]] = defaultdict(list)
         for r in records:
             records_by_word[r.word_id].append(r)