错题本（cuotiben）

Turn a wrong problem into a structured study record: analyze it, explain the
error, generate similar practice problems, and keep everything in a searchable
local 错题本 that can be exported to a Chinese-friendly PDF.

When to use

• User pastes text or shares a photo of a wrong problem and asks for 解析 / 讲解.
• User asks for 相似题 / 同类题 / 变式题 based on a problem.
• User wants to 整理错题 / 建错题本 / 复习错题 / 按学科或知识点搜索.
• User wants to 导出 PDF 错题本.

Workflow

1. 录入并分析（核心）

Accept either an image (photo of the problem) or text.

• If an image path is given, read it with multimodal capability and transcribe the
  problem faithfully (keep math notation; describe diagrams in words).
• Follow the analysis template in references/schema.md to produce, in one
  structured answer:
  1. 学科 (subject) and 知识点 (knowledge point) — pick a short,
  consistent label (e.g. 数学 / 二次函数) so later filtering works.
  2. 错误原因 — the misconception that leads to the wrong answer.
  3. 解析 — step-by-step correct solution.
  4. 答案.
  5. Exactly 2 道相似题 — same knowledge point & difficulty, varied
  numbers/context; each with its own 答案 (and a brief 解析).

1.5 是否生成交互程序（主动判断）

For concepts that are geometric / spatial / dynamic — where seeing or
manipulating beats reading — proactively build a self-contained interactive
HTML and present it (write the file, then present_files to open a live
preview). Do NOT ask first when the concept clearly benefits. Strong candidates:
圆面积推导, 函数图像与变换, 几何图形变换, 运动/轨迹, 概率模拟.
Keep the HTML single-file, dependency-free, Chinese UI, light theme.
Also generate an interactive for the 2 相似题 whenever they share the same
interactive-friendly concept — prefer folding them into the SAME html as a
practice mode (preset buttons that load each 相似题's numbers and let the
student self-check against the live computed result).

2. 存储

Persist the record so it becomes part of the 错题本. Build the JSON object
(schema in references/schema.md) and append it:

python3 ~/.workbuddy/skills/cuotiben/scripts/add_mistake.py --data '<json>'

The script assigns an id + created_at and writes to
~/.workbuddy/cuotiben_data/mistakes.json by default (override with --store).

3. 复习 / 搜索

• List or filter:

python3 ~/.workbuddy/skills/cuotiben/scripts/search_mistakes.py --subject 数学 --keyword 函数 --format list

• Output formats: list (compact), md (readable report), json (raw).
• For 重复练习: pick records (optionally filtered), re-ask the 相似题 to the
  user, then reveal answers and 解析.

4. 导出 PDF

python3 ~/.workbuddy/skills/cuotiben/scripts/export_pdf.py --out ~/Desktop/错题本.pdf

Renders each record with a system CJK font (no garbled Chinese). Requires
reportlab — the script auto-installs it if missing.

Notes

• The 错题本 is a single JSON file at ~/.workbuddy/cuotiben_data/mistakes.json;
  it persists across sessions and is independent of any project.
• Keep 学科 / 知识点 labels consistent across entries to make search/filter useful.