[soltros]

Windows archive enumeration fails while loading Linux's libzstd.so.1 even though the project zstandard package is already installed. Enumeration now prefers that cross-platform Python package, retaining native libzstd fallback for installations without it.

Related: #93; Windows failure observed in #109.

The Python backend tries an unbound frame then each supplied raw/trained dictionary, checks decompressor EOF so truncated data cannot be accepted as a successful partial result, and reports invalid frames as ValueError. Plain input remains unchanged. Native fallback searches platform-appropriate library names and explains how to install a missing dependency.

Synthetic bake fixtures use the same installed package for compression, including dictionary frames. Python 3.14 compression and CLI fallback remain available when the package is absent. CLI dictionary files are closed before subprocess use, avoiding Windows open-file sharing problems. A requested dictionary fixture must be produced successfully; failure is no longer silently counted as a skip. The suite explicitly declares the existing Python dependency.

Validation: seven new synthetic regression cases pass, covering known/unknown size, required trained dictionary and candidate ordering, raw dictionary, truncated/invalid frames, plain bytes, no shared-library load, and missing-library diagnostics. Existing bake-ds enumeration/parity/key checks pass; native translate/bank skipped without a built tool. Full local suite: 273 passed, 12 failed, 51 skipped. No game data or derived outputs are included.

Final platform validation: these exact changes passed together in #114. Windows: 317 passed, 0 failed, 21 skipped; Linux: 329 passed, 0 failed, 9 skipped. Actual Mimo and skeleton translation tests passed on both platforms. Windows Builder, Linux AppImage, actionlint and both focused shader jobs also passed. Standalone branch failures were the separately repaired inherited defects; no checks were removed or disabled.