Rethlas-OSV 0.6.1

This patch updates the bundled OSVerify core to v0.6.1, including the external-source retrieval fixes.

• Read ordinary web pages, GitHub Markdown and source-code files.
• Preserve page bodies previously mistaken for navigation, and literal HTML/TeX examples in text files.
• Keep source types distinct from verified claims and report retrieval failures more precisely.
• Exercise the literature helper and file lock in the compiled-app smoke tests.

Downloads:

• Apple silicon Macs: Rethlas-OSV-0.6.1-arm64.dmg
• Intel Macs: Rethlas-OSV-0.6.1-x86_64.dmg
• Linux x86-64: Rethlas-OSV-0.6.1-linux-x86_64.tar.gz

The desktop app remains beta. macOS builds use ad-hoc signing unless a Developer ID is configured; see the README for first-launch instructions. Native Windows desktop packaging is not included.

Start a new review or generation run to use the updated core. Resume historical runs with their original app/core version so frozen provenance remains intact.

Validation: 104 Rethlas-OSV tests and 439 OSVerify core tests passed, as did Ruff and the compiled-app checks on all three platforms. Downloaded installers matched GitHub's SHA-256 digests; SHA256SUMS.txt is attached for independent download verification.