Add zst support to archiver library

[Copilot]

The Lua archiver library did not recognize or extract zstd-compressed tar archives. Plugins using archiver.decompress() could not handle SDK distributions packaged as .tar.zst or .tzst.

• Archive support

  • Added .tar.zst and .tzst detection in the shared decompressor factory.
  • Added zstd tar extraction via github.com/klauspost/compress/zstd.

• Extraction behavior

  • Preserves existing tar archive behavior by stripping a detected common root directory.
  • Supports flat archives without dropping path components.
  • Rejects path traversal entries before writing files.

• Docs and coverage

  • Updated English and Chinese archiver library docs to list zst formats.
  • Added focused tests for format selection, extraction, common-root stripping, and traversal rejection.

Example plugin usage:

local archiver = require("vfox.archiver")
local err = archiver.decompress("node-v22.0.0-linux-x64.tar.zst", "install-dir")

[bytemain]

@aooohan https://github.com/astral-sh/python-build-standalone 打包出来的 python 很多都是 .tar.zst 格式的，目前 vfox 还不支持。

   },
    {
      "implementation": "cpython",
      "version": "3.10.20",
      "display_version": "3.10.20",
      "variant": "default",
      "release": "20260414",
      "filename": "cpython-3.10.20+20260414-aarch64-unknown-linux-gnu-pgo+lto-full.tar.zst",
      "url": "https://github.com/astral-sh/python-build-standalone/releases/download/20260414/cpython-3.10.20%2B20260414-aarch64-unknown-linux-gnu-pgo%2Blto-full.tar.zst",
      "platform": {
        "os": "linux",
        "arch": "aarch64",
        "libc": "gnu"
      },
      "asset": {
        "size": 66062262,
        "content_type": "application/octet-stream",
        "created_at": "2026-04-14T17:26:12Z",
        "updated_at": "2026-04-14T17:26:15Z",
        "sha256": "cbd9d1d45cabb7268b628075f58e8b2cc7de47b95834daa2f1e73a0645bf2d0e"
      }
    }
  ]
}

[codecov]

Codecov Report

❌ Patch coverage is 50.98039% with 50 lines in your changes missing coverage. Please review.
✅ Project coverage is 25.62%. Comparing base (8182390) to head (daa537a).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/shared/util/decompressor.go	50.98%	33 Missing and 17 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #663      +/-   ##
==========================================
+ Coverage   25.17%   25.62%   +0.45%     
==========================================
  Files          83       83              
  Lines        5693     5795     +102     
==========================================
+ Hits         1433     1485      +52     
- Misses       4082     4115      +33     
- Partials      178      195      +17     

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[Copilot]

Pull request overview

Adds .tar.zst / .tzst (zstd-compressed tar) support to the shared Lua archiver decompression pipeline so plugins can decompress SDK distributions packaged with zstd.

Changes:

• Introduces a new ZstdTarDecompressor using github.com/klauspost/compress/zstd and wires it into NewDecompressor() via .tar.zst / .tzst suffix detection.
• Adds tests covering decompressor selection, extraction, common-root stripping, and traversal rejection.
• Updates English + Simplified Chinese archiver docs to list zstd formats and updates go.mod to include the zstd dependency as a direct requirement.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
internal/shared/util/decompressor.go	Adds zstd-tar decompressor implementation + file suffix detection.
internal/shared/util/decompressor_test.go	Adds tests + helper to generate .tar.zst fixtures.
go.mod	Promotes github.com/klauspost/compress to a direct dependency.
docs/plugins/library/archiver.md	Documents .tar.zst / .tzst support (EN).
docs/zh-hans/plugins/library/archiver.md	Documents .tar.zst / .tzst support (ZH-Hans).

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