Ship native iOS app, Wiki/TTS backend, and skeleton loading UX.

Replace the WebView shell with SwiftUI screens, add account-scoped Wiki and TTS APIs with adaptive review and photo scan support, and keep web/iOS pages usable while data loads asynchronously.

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

backend/services/text_utils.py

@@ -0,0 +1,10 @@
+import re
+
+
+def normalize_en_answer(text: str) -> str:
+    """英文拼写/短语答案：去首尾空白、小写、连续空白压成单个空格。"""
+    return re.sub(r"\s+", " ", (text or "").strip().lower())
+
+
+def en_answers_match(user_answer: str, correct_answer: str) -> bool:
+    return normalize_en_answer(user_answer) == normalize_en_answer(correct_answer)