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/schemas.py

@@ -47,6 +47,7 @@ class TranslateResponse(BaseModel):
     phonetic: Optional[str] = None
     example_en: Optional[str] = None
     example_cn: Optional[str] = None
+    found: bool = True
 
 
 # Words
@@ -67,6 +68,8 @@ class WordUpdate(BaseModel):
 class WordOut(BaseModel):
     id: int
     user_id: int
+    book_id: int = 0
+    book_entry_id: Optional[int] = None
     source_text: str
     target_text: str
     source_lang: str
@@ -195,6 +198,8 @@ class QuizQuestion(BaseModel):
 class DailyQuizResponse(BaseModel):
     questions: list[QuizQuestion]
     total: int
+    track: str = "accumulation"
+    book_id: Optional[int] = None
 
 
 class QuizAnswerRequest(BaseModel):
@@ -223,6 +228,70 @@ class QuizStatsResponse(BaseModel):
     daily_target: int
     today_completed: int
     streak_days: int
+    track: str = "accumulation"
+    book_id: Optional[int] = None
+
+
+# Word books
+class WordBookOut(BaseModel):
+    id: int
+    slug: str
+    title: str
+    description: Optional[str] = None
+    level: str
+    word_count: int
+    unit_count: int
+    sort_order: int
+    daily_target: int
+    master_required_count: int
+    weak_wrong_threshold: int
+    learn_mode: str
+
+    class Config:
+        from_attributes = True
+
+
+class WordBookUnitOut(BaseModel):
+    unit: int
+    title: Optional[str] = None
+    word_count: int
+
+
+class WordBookDetailOut(WordBookOut):
+    units: list[WordBookUnitOut] = []
+
+
+class WordBookProgressOut(BaseModel):
+    book_id: int
+    total: int
+    introduced: int
+    mastered: int
+    learning: int
+    locked: int
+
+
+class BookPracticeSettingsOut(BaseModel):
+    book_id: int
+    daily_target: int
+    master_required_count: int
+    weak_wrong_threshold: int
+
+
+class ActiveBookOut(BaseModel):
+    book: Optional[WordBookOut] = None
+    progress: Optional[WordBookProgressOut] = None
+    settings: Optional[BookPracticeSettingsOut] = None
+
+
+class SetActiveBookRequest(BaseModel):
+    book_id: int = Field(ge=1)
+
+
+class BookPracticeSettingsUpdate(BaseModel):
+    book_id: Optional[int] = Field(None, ge=1)
+    daily_target: Optional[int] = Field(None, ge=5, le=50)
+    master_required_count: Optional[int] = Field(None, ge=1, le=10)
+    weak_wrong_threshold: Optional[int] = Field(None, ge=1, le=10)
 
 
 # Settings