support Android SDK build-tools apksigner v35/v36; fix #96

[XenoAmess]

Summary

Fix #96: support Android SDK build-tools apksigner v35 (and later v36).

Root cause

apksigner v35+ re-aligns uncompressed ZIP entries while signing and writes a
dedicated 0xd935 alignment extra field only in the local file header (the
central directory keeps the pre-signing extra fields). This breaks the
local header extra == central directory extra invariant that ZipPatch's
reconstruction relies on, so the patched APK was not byte-by-byte equal to the
released (re-signed) APK.

Fix

• ZipDiff now saves the target's local file header info (local header
  offset + local header extra field, per entry) into the diff, using a new
  diff format tag ZiPat2&, whenever the local header extra differs from
  the central directory extra (i.e. apksigner v35/v36-signed targets).
• ZipPatch writes those local headers byte-verbatim at their saved offsets,
  so the patched APK is byte-by-byte equal.
• Old ZiPat1& diffs stay unchanged for v34 / not-re-signed targets, so old
  ZipPatch keeps working for them; new v1.9.0+ ZipPatch reads both formats.
  Old ZipPatch cleanly rejects ZiPat2& (version check), never silently
  corrupting.
• Also fix UnZipper_getHugePageAlign for the v35 layout (local header length
  derived when CD extra != local extra).

Tests

• New builds/apksigner_roundtrip_test.sh + CI job apksigner-roundtrip-test
  running ApkNormalized -> apksigner -> ZipDiff -> ZipPatch round-trips for
  build-tools 34.0.0 / 35.0.0 / 36.1.0, verifying the patched APK is
  byte-by-byte equal and its signature verifies.
  • v34: diff stays ZiPat1& (legacy, old tools compatible)
  • v35/v36: diff uses ZiPat2& (new format)

Backward compatibility matrix is documented in docs/issue-96-fix-plan.md.

[XenoAmess]

do you have any ohter test cases we shall cover for this? I can also try adding them into the ci.

[sisong]

非常感谢你的PR，它解决了库对新版本apksigner的兼容问题,这对有需求或新采纳这个方案的团队很有帮助。
但这个修改对旧的patcher不兼容，当然这也是比较容易想到的直接解决问题的方案。

我也考虑过修复这个和apksigner的兼容问题，但因为要求升级patcher端，所以就想对ApkDiffPatch进行一次更大范围的更新(v2.0)，一并解决本库已知的其他设计问题：

1. patcher端解除对zip格式或apk签名的耦合 （现在和zip格式、apk签名的耦合过于严重）
2. patcher端在多线程并行时更快，并且内存占用可控 （最大内存占用控制在 threadNum x O(1); 现在是threadNum x O(EntryFileSize)）
3. ApkNormalized 标准化apk时支持 libdeflate 压缩，从而patch还原时可以更快(推荐)或者apk包更小(不推荐)。
4. 尝试支持对 arm64-v8a和armeabi-v7a的.so文件、安卓.dex文件进行针对性的优化(反汇编)，用以得到更小的补丁。

[XenoAmess]

非常感谢你的PR，它解决了库对新版本apksigner的兼容问题,这对有需求或新采纳这个方案的团队很有帮助。 但这个修改对旧的patcher不兼容，当然这也是比较容易想到的直接解决问题的方案。

我也考虑过修复这个和apksigner的兼容问题，但因为要求升级patcher端，所以就想对ApkDiffPatch进行一次更大范围的更新(v2.0)，一并解决本库已知的其他设计问题：

1. patcher端解除对zip格式或apk签名的耦合 （现在和zip格式、apk签名的耦合过于严重）
2. patcher端在多线程并行时更快，并且内存占用可控 （最大内存占用控制在 threadNum x O(1); 现在是threadNum x O(EntryFileSize)）
3. ApkNormalized 标准化apk时支持 libdeflate 压缩，从而patch还原时可以更快(推荐)或者apk包更小(不推荐)。
4. 尝试支持对 arm64-v8a和armeabi-v7a的.so文件、安卓.dex文件进行针对性的优化(反汇编)，用以得到更小的补丁。

(原来这边说中文啊!)
很期待!加油喵!