feat(core,github-action): configurable git tag format

[goulvenclech]

Closes #190 and #239. Made git tag format configurable via new tag_format and short_tags_format options under [git]. Templates accept {ecosystem}, {package_name}, and {version}.

sampo publish now also detects cross-ecosystem tag conflicts: it errors when two packages would produce the same git tag for the release in flight, and warns when packages share a name across ecosystems with a template that doesn't include {ecosystem} (a future version bump would silently collide). Both diagnostics suggest setting tag_format = "{ecosystem}-{package_name}-v{version}" as the fix.

What has changed?

• sampo publish now errors when two packages would render to the same git tag for the release in flight, and warns when packages share a name across ecosystems with a template that doesn't include {ecosystem} (a future bump that aligns versions would silently collide). Both diagnostics suggest setting tag_format = "{ecosystem}-{package_name}-v{version}".
• The GitHub Action defers to Config::default().parse_tag instead of its own parser, so a custom tag_format is honoured wherever tags are read back.

How is it tested?

Unit tests for TagTemplate (parsing, rendering, matching, non-ASCII separators, prereleases with -v), config round-trips with both templates set, and check_tag_conflicts covering certain-conflict / potential-conflict / silent / short-tags-hint / multi-ecosystem cases. Full workspace: 531 passing.

How is it documented?

crates/sampo/README.md documents both options and the conflict-detection behaviour with a copy-pasteable fix.

[sampo-s-bot]

🧭 Changeset detected

Merging this PR will release the following updates:

sampo (Cargo) — minor version bump

Minor changes

• Made git tag format configurable via new tag_format and short_tags_format options under [git]. Templates accept {ecosystem}, {package_name}, and {version}.

  sampo publish now also detects cross-ecosystem tag conflicts: it errors when two packages would produce the same git tag for the release in flight, and warns when packages share a name across ecosystems with a template that doesn't include {ecosystem} (a future version bump would silently collide). Both diagnostics suggest setting tag_format = "{ecosystem}-{package_name}-v{version}" as the fix.

sampo-core (Cargo) — minor version bump

Minor changes

• Made git tag format configurable via new tag_format and short_tags_format options under [git]. Templates accept {ecosystem}, {package_name}, and {version}.

  sampo publish now also detects cross-ecosystem tag conflicts: it errors when two packages would produce the same git tag for the release in flight, and warns when packages share a name across ecosystems with a template that doesn't include {ecosystem} (a future version bump would silently collide). Both diagnostics suggest setting tag_format = "{ecosystem}-{package_name}-v{version}" as the fix.

sampo-github-action (Cargo) — minor version bump

Minor changes

• Made git tag format configurable via new tag_format and short_tags_format options under [git]. Templates accept {ecosystem}, {package_name}, and {version}.

  sampo publish now also detects cross-ecosystem tag conflicts: it errors when two packages would produce the same git tag for the release in flight, and warns when packages share a name across ecosystems with a template that doesn't include {ecosystem} (a future version bump would silently collide). Both diagnostics suggest setting tag_format = "{ecosystem}-{package_name}-v{version}" as the fix.

[Princesseuh]

I don't think this is the proper solution. Sampo (and similar tools) already kinda suffer from a configuration churn due to having to support a bunch of different setup, and so the default experience should be as seamless:tm: as possible. Pit of success and all that.

I think a better solution, even though it's not intuitive is to instead force users that do encounter the edge case to configure Sampo differently. For instance for Sätteri, publishing would error because it could conflict (even if it doesn't for that specific release), telling me to configure tag_format with perhaps a suggestion.