BabelDOC v0.6.1

Highlights

Fixed recursion-depth failures that could occur while translating PDFs with
deeply linked paragraph context.
修复了翻译某些 PDF 时，由深层段落上下文触发的递归深度失败。
Added defensive depth and cycle guards for several PDF parsing paths,
including Form XObject execution, font resource projection, token parsing,
object parsing, and token serialization.
为多个 PDF 解析路径增加了深度与环检测保护，包括 Form XObject 执行、字体资源投影、
token 解析、object 解析和 token 序列化。
Reduced risky deep-copy behavior in translation context handling and formula
relocation, improving robustness on complex PDF object graphs.
减少了翻译上下文和公式重排中的高风险深拷贝行为，提升复杂 PDF 对象图上的稳健性。

Title context used by the translator now stores a compact immutable snapshot
instead of copying the full paragraph object graph.
译文上下文中的标题信息现在保存紧凑的不可变快照，而不是复制完整段落对象图。
Form XObject expansion now stops on recursive or excessively deep structures
instead of exhausting the Python call stack.
Form XObject 展开遇到递归或过深结构时会停止，而不是耗尽 Python 调用栈。
Deeply nested PDF token and object structures now fail with controlled parser
errors instead of uncaught recursion errors.
深层嵌套的 PDF token 与 object 结构现在会以受控解析错误失败，而不是抛出未控制的递归错误。
Formula relocation now rebuilds the small objects it needs to move instead of
deep-copying full rendering state.
公式重排现在只重建需要移动的小对象，不再深拷贝完整渲染状态。

This release is intended as a focused reliability update for the v0.6 parser
rewrite line.
本版本是针对 v0.6 解析器重写线的可靠性修复版本。
Extremely recursive or malformed PDF structures may now have only the unsafe
nested portion skipped or reported as a parser error.
对极端递归或损坏的 PDF 结构，BabelDOC 现在可能跳过不安全的嵌套部分，或报告解析错误。