feat: 新增从真题库生成举一反三变式题

Author: margrop

README.en.md

@@ -30,7 +30,7 @@ An AI-powered notebook for the questions you got wrong. Snap a photo or type a q
 
 - **🆓 Works with free accounts**: choose the "MiniMax Code OAuth" channel and sign in with a MiniMax Code account in the browser, with no API key to buy; the app checks in every day to collect credits (see [MiniMax Code OAuth](#minimax-code-oauth)). New Volcengine users also get a [free inference quota](#volcengine-free-trial).
 - **📚 A complete review loop**: auto-graded similar questions, AI mastery estimates, daily review at Ebbinghaus intervals, and printable exams built from your mistakes with per-question results.
-- **🗂️ Shared question banks**: the new Question Bank page downloads primary, junior-high and senior-high subject banks from [margrop/wrong-notebook-question-bank](https://github.com/margrop/wrong-notebook-question-bank). Imported questions stay in the bank by default and do not become mistakes; you can optionally add them to a notebook. Practice can pick a bank question by knowledge point without spending AI quota.
+- **🗂️ Shared question banks**: the new Question Bank page downloads primary, junior-high and senior-high subject banks from [margrop/wrong-notebook-question-bank](https://github.com/margrop/wrong-notebook-question-bank). Imported questions stay in the bank by default and do not become mistakes; you can optionally add them to a notebook. Practice can pick a bank question by knowledge point without spending AI quota, or choose **Variant from bank** to have AI generate a variant seeded by a selected bank question.
 - **📦 Install anywhere**: Docker image (amd64 / arm64), npm, Windows, macOS, Linux, fnOS, Synology/QNAP packages, Android phones and tablets (standalone or client), or add it to your home screen as a PWA.
 
 > This repository is a fork of [wttwins/wrong-notebook](https://github.com/wttwins/wrong-notebook); most of the features above and below were added here. The built-in knowledge-point library follows the Chinese K-12 curriculum (primary, junior high and senior high school). The interface is available in Simplified Chinese and English.
@@ -168,7 +168,7 @@ Practice statistics show total practice, accuracy (correct / attempted) and acti
 
 ### Review and practice
 
-- **🔄 Practice similar questions**: generate variant questions (fill-in-the-blank or free response) on the same knowledge point, choose the difficulty and submit an answer: it is checked automatically (local matching checks identical conclusions only when no reasoning is required; proofs and justification questions go to AI to check the reasoning, and other answers are compared by AI with the reference answer), and you can change the result before saving. The most recently generated question and solution are kept for each mistake and shown directly next time; click Regenerate for a new one.
+- **🔄 Practice similar questions**: generate variant questions (fill-in-the-blank or free response) on the same knowledge point, choose the difficulty and submit an answer; practice can also pick a bank question by knowledge point, or select one first and let AI generate a variant of it. Answers are checked automatically (local matching checks identical conclusions only when no reasoning is required; proofs and justification questions go to AI to check the reasoning, and other answers are compared by AI with the reference answer), and you can change the result before saving. The most recently generated question and solution are kept for each mistake and shown directly next time; click Regenerate for a new one.
 - **📈 Mastery probability**: AI estimates how likely you have mastered each question from the answer history of practice and exams. Questions fall into three states: **To Review** (no practice records yet), **Reviewing** (has records, probability below the mastered threshold) and **Mastered** (has records, probability at or above the threshold). The threshold is 50% by default and each user can adjust it in settings.
 - **📅 Daily review**: each question is scheduled at Ebbinghaus intervals of 1, 2, 4, 7, 15 and 30 days. A correct answer moves it to the next interval; a wrong answer starts over. The **Review** page lists questions due today (earliest first) with paging at both the top and bottom, and **Review in order** walks through them one by one: compare your work with the answer, then mark it right (marked as mastered) or wrong (enter the mistake reason); the home page shows how many are due.
 - **🧾 Mistake exams**: draw questions at random by notebook, knowledge point, question type and mastery, and build a printable exam from similar questions (AI-generated) or original questions (no AI quota used, ready to print immediately). Turn on "Generate A/B papers simultaneously" to create two parallel papers with non-overlapping questions in one go. Each question can have its own score and the paper total is summed automatically; a "Group by question type" switch groups questions into sections such as choice and fill-in-the-blank. After finishing, enter results per question; they are added to the original question's answer history.

README.md

@@ -30,7 +30,7 @@
 
 - **🆓 免费账号就能用**：选择「MiniMax Code OAuth」渠道，用 MiniMax Code 账号网页登录即可使用，不需要购买 API Key，应用每天自动签到领取积分（见 [MiniMax Code OAuth](#minimax-code-oauth)）；火山引擎新用户也有[免费推理额度](#火山引擎免费试用)。
 - **📚 复习闭环**：举一反三变式题自动判题、AI 评估掌握概率、艾宾浩斯间隔的今日复习、按错题组卷打印并回填结果。
-- **🗂️ 共享真题库**：新增「真题库」页，可从 [margrop/wrong-notebook-question-bank](https://github.com/margrop/wrong-notebook-question-bank) 下载小学、初中、高中多学科题库包；导入默认只进入真题库、不产生错题，也可勾选同时写入错题本。举一反三可按知识点从真题库选题，不消耗 AI 额度。
+- **🗂️ 共享真题库**：新增「真题库」页，可从 [margrop/wrong-notebook-question-bank](https://github.com/margrop/wrong-notebook-question-bank) 下载小学、初中、高中多学科题库包；导入默认只进入真题库、不产生错题，也可勾选同时写入错题本。举一反三可按知识点从真题库选题（不消耗 AI 额度），也可选「真题库变式」：先选出题库题目，再由 AI 以该题为原题生成变式题。
 - **📦 多平台安装**：Docker 镜像（amd64 / arm64）、npm、Windows、macOS、Linux、飞牛OS、群晖/威联通套件、安卓手机与平板（单机版或客户端），也可添加到手机主屏幕（PWA）。
 
 > 本仓库 fork 自 [wttwins/wrong-notebook](https://github.com/wttwins/wrong-notebook)，在其基础上增加了上述及下文列出的大部分功能。
@@ -168,7 +168,7 @@
 
 ### 复习与练习
 
-- **🔄 举一反三**：基于错题生成同知识点的变式题（填空或解答题），可选难度；提交答案后自动判题（不要求过程且结论一致时本地判对，证明或说明理由题交给 AI 核验论证，其余情况由 AI 对照标准答案判定并给出依据），保存前可修改结果；每道错题暂存最近一次生成的变式题与解答，再次进入时直接显示，需要新题再点「重新生成」。
+- **🔄 举一反三**：基于错题生成同知识点的变式题（填空或解答题），可选难度；也可从真题库按知识点选题，或先选题库题目再由 AI 生成该题的变式题。提交答案后自动判题（不要求过程且结论一致时本地判对，证明或说明理由题交给 AI 核验论证，其余情况由 AI 对照标准答案判定并给出依据），保存前可修改结果；每道错题暂存最近一次生成的变式题与解答，再次进入时直接显示，需要新题再点「重新生成」。
 - **📈 掌握概率**：根据举一反三和试卷的作答历史，由 AI 评估每道题的已掌握概率。错题分为三种状态：没有举一反三记录的为「待复习」，有记录且掌握概率低于已掌握阈值的为「复习中」，达到阈值的为「已掌握」。阈值默认 50%，每个用户可在设置中单独调整。
 - **📅 今日复习**：按 1、2、4、7、15、30 天的艾宾浩斯间隔安排每道错题的复习，做对进入下一轮间隔，做错从头开始。导航栏的「复习」页列出今天到期的错题（最早到期的在前），可「按顺序复习」逐题查看答案并记录做对或做错（做对直接标记为已掌握，做错填写错误原因），顶部和底部都能翻页；首页显示今日待复习数量。
 - **🧾 错题试卷**：按错题本、知识点、题型和掌握情况随机抽题，可选择「举一反三」（AI 生成新题）或「原题直出」（直接使用原题，不消耗 AI 额度，立即可打印）；可打开「同时生成 A/B 卷」一次生成两份题目互不重复的平行卷；每道题可单独设置分值，试卷自动汇总总分，详情页可开启「按题型分大题」按选择题、填空题等分组排版；做完后可按题录入结果，结果计入原题的作答历史。

doc/wiki/Home.md

@@ -30,7 +30,7 @@ Smart Wrong Notebook（智能错题本）把拍照或文字录入的错题整理
 - Markdown、LaTeX、SVG 配图、带语音讲解的 SVG 动画及可选的 GeoGebra 动态演示。
 - 题库文件导入（JSON / Word / Excel / CSV / PDF，可「按原样入库」不调用 AI）与选中错题导出（JSON / Excel / Word）。
 - 举一反三与 AI 判题、今日复习、错题组卷、作答历史、掌握概率、学习统计和打印导出。
-- 共享真题库：从 [共享题库仓库](https://github.com/margrop/wrong-notebook-question-bank) 下载小学/初中/高中题库包，导入默认不进入错题；举一反三可按知识点从题库选题。
+- 共享真题库：从 [共享题库仓库](https://github.com/margrop/wrong-notebook-question-bank) 下载小学/初中/高中题库包，导入默认不进入错题；举一反三可按知识点从题库选题，或基于题库题目生成变式题。
 - 多用户隔离、每日 AI 次数限制、管理员设置、个人偏好、Openclaw 批量导入与 MCP 服务。
 - 全新安装通过一次性初始化链接（飞牛OS 为安装向导）设置管理员，不预置固定密码；随后由安装向导引导配置 AI、创建错题本。
 

doc/wiki/Practice-and-Exams.md

@@ -9,7 +9,7 @@
 
 ## 举一反三
 
-从错题详情进入举一反三，先选择出题来源与难度：AI 生成考查相同知识点的变式题，或从已导入的真题库按知识点选题。AI 生成的题型限定为填空题或解答题，题目内容不应携带题号、分值或选择题选项；真题库选题保留原题题型、选项、答案与解析，优先匹配错题的知识点标签，同分时按所选难度挑选，并排除该错题最近练习过的题目。真题库选题不调用 AI、不消耗额度；没有匹配题目时提示先导入题库或改用 AI 生成。
+从错题详情进入举一反三，先选择出题来源与难度：AI 生成考查相同知识点的变式题；从已导入的真题库按知识点选题；或选「真题库变式」，先按知识点选出题库题目，再由 AI 以该题为原题生成变式题（消耗 AI 额度，选题失败时不消耗）。AI 生成的题型限定为填空题或解答题，题目内容不应携带题号、分值或选择题选项；真题库选题保留原题题型、选项、答案与解析，优先匹配错题的知识点标签，同分时按所选难度挑选，并排除该错题最近练习过的题目。真题库选题不调用 AI、不消耗额度；没有匹配题目时提示先导入题库或改用 AI 生成。
 
 先独立作答，再查看答案与解析，并记录做对或做错。记录会关联原题，用于回看练习历史和评估掌握情况。
 

doc/wiki/en/Home-en.md

@@ -30,7 +30,7 @@ This Wiki covers [margrop/wrong-notebook](https://github.com/margrop/wrong-noteb
 - Markdown, LaTeX, SVG figures, SVG animated explanations with voice narration and optional GeoGebra interactive demos.
 - Question bank file import (JSON / Word / Excel / CSV / PDF, with an as-is mode that skips AI calls) and exporting selected questions as JSON, Excel or Word.
 - Similar-question practice with AI grading, daily review, exam papers built from mistakes, answer history, mastery probability, statistics and print export.
-- Shared question banks: download primary, junior-high and senior-high packages from the [shared bank repository](https://github.com/margrop/wrong-notebook-question-bank); imported questions stay in the bank by default, and practice can pick by knowledge point.
+- Shared question banks: download primary, junior-high and senior-high packages from the [shared bank repository](https://github.com/margrop/wrong-notebook-question-bank); imported questions stay in the bank by default, and practice can pick by knowledge point or generate a variant seeded by a bank question.
 - Per-user data isolation, daily AI limits, admin settings, personal preferences, Openclaw batch import and an MCP server.
 - Fresh installs set up the admin with a one-time setup link (the install wizard on fnOS) instead of a fixed default password, then the setup wizard helps configure AI and create a notebook.
 

doc/wiki/en/Practice-and-Exams-en.md

@@ -9,7 +9,7 @@ The shared index and package format are documented by `index.json` and `schema/q
 
 ## Similar-question practice
 
-Open similar-question practice from a question's detail page, then choose the question source and difficulty: AI generates a variant testing the same knowledge points, or practice picks a question from an imported bank by knowledge point. AI-generated questions are fill-in-the-blank or free-response, without a question number, score or multiple-choice options; bank questions keep their original type, options, answer and analysis. Bank selection prefers questions whose knowledge points match the mistake's tags, prefers the chosen difficulty among equal matches, and skips questions practised recently for that mistake. It does not call the AI or spend quota; when nothing matches, the app asks you to import a bank or use AI generation.
+Open similar-question practice from a question's detail page, then choose the question source and difficulty: AI generates a variant testing the same knowledge points; practice picks a question from an imported bank by knowledge point; or **Variant from bank** first selects a bank question by knowledge point and has AI generate a variant seeded by it (spends AI quota; selection failure spends none). AI-generated questions are fill-in-the-blank or free-response, without a question number, score or multiple-choice options; bank questions keep their original type, options, answer and analysis. Bank selection prefers questions whose knowledge points match the mistake's tags, prefers the chosen difficulty among equal matches, and skips questions practised recently for that mistake. It does not call the AI or spend quota; when nothing matches, the app asks you to import a bank or use AI generation.
 
 Answer on your own first, then view the answer and analysis and record whether you got it right. Records are linked to the original question for reviewing practice history and evaluating mastery.