fix: restore get_subs_list_keyboard helper

SubMind.py

@@ -263,6 +263,27 @@ def _parse_category_id_from_callback(data: str) -> int | None:
     return int(payload) if payload.isdigit() else None
 
 
+async def get_subs_list_keyboard(user_id: int, category_filter: str = None) -> InlineKeyboardMarkup:
+    with get_db_connection() as conn:
+        cursor = conn.cursor()
+        query, params = "SELECT id, name FROM subscriptions WHERE user_id = ? ", [user_id]
+        if category_filter:
+            query += "AND category = ? "
+            params.append(category_filter)
+        query += "ORDER BY next_due ASC"
+        cursor.execute(query, tuple(params))
+        subs = cursor.fetchall()
+    if not subs:
+        return None
+    buttons = [InlineKeyboardButton(name, callback_data=f'view_{sub_id}') for sub_id, name in subs]
+    keyboard = [buttons[i:i + 2] for i in range(0, len(buttons), 2)]
+    if category_filter:
+        keyboard.append([InlineKeyboardButton("« 返回分类列表", callback_data='list_categories')])
+    else:
+        keyboard.append([InlineKeyboardButton("🗂️ 按分类浏览", callback_data='list_categories')])
+    return InlineKeyboardMarkup(keyboard)
+
+
 def _clear_action_state(context: CallbackContext, keys: list[str]):
     for key in keys:
         context.user_data.pop(key, None)