ci: optimize release packaging workflows

[CaseyLabs]

Summary

• Gate CI Go format/vet and Go tests on Go-related inputs: *.go, go.mod, go.sum, Makefile, and shared Go CI workflow/action files.
• Keep JavaScript lint conditional on JavaScript lint inputs.
• Add Docker package change detection so image builds only run when build-relevant files change, including .dockerignore, and skip GHCR login on pull requests.
• Improve release notes generation with current-tag asset links, safer generated Markdown output, and configurable datafiles archive text.
• Ensure stable release builds are dispatched from master, and keep release cross-builds out of PR CI.
• Add generated-output cleanliness verification to the shared Go checks action.
• Support armv7l/armv8l hosts in the Linux/macOS installer's Go toolchain download mapping.

Validation

• actionlint .github/workflows/*.yml
• bash -n .github/scripts/*.sh scripts/install.sh
• zsh -n scripts/install.sh
• git diff --check
• Focused .dockerignore Docker detection regex check
• Focused Go-related CI gate regex check
• Release-notes dry run with RELEASE_NOTES_SKIP_GH=true, confirming releases/tag/<tag> links, Markdown literals, and configurable datafiles archive text render correctly