Summary

Align the CI and release pipelines with the new reusable workflow contracts and preserve the release-tag flow brought from main.

What changed

• consolidate Linux and macOS reusable build invocations around OS-level matrix workflows
• add Linux package format selection for manual runs: gzip, appimage, or gzip + appimage
• switch release manual inputs from multiple booleans to a single release_mode choice
• keep tag creation before builds and cleanup on downstream failure
• resolve the release.yml merge conflict by preserving both the branch workflow updates and the tag-management flow from main

Notes for review

• Linux CI still requests both package formats automatically
• release changelog detection now excludes the in-flight release tag so comparisons use the previous published tag