chore(EL-1547): set the package version to 3.1.1 so the release can publish

[mariusz-peplinski]

JIRA TASK: EL-1547 - Clean up showroom developer console logs and warnings

📦 The 3.1.0 release never reached npm

3.1.0 was tagged and a GitHub release was cut, but Publish to NPM failed (run 32855740962):

npm error You cannot publish over the previously published versions: 3.0.0.

The release tag pointed at a commit whose package.json still said 3.0.0, so npm publish tried to republish the existing version and npm rejected it. npm latest is still 3.0.0, which means the quiet-OAuth-logs work in #31 has not reached any consumer.

WHAT

One line: package.json version → 3.1.1.

WHY 3.1.1 AND NOT 3.1.0

Going to a fresh patch avoids deleting and re-cutting the existing 3.1.0 tag and release. Nothing was ever published as 3.1.0, so no consumer can be holding it, and npm does not require contiguous versions — 3.0.0 → 3.1.1 publishes cleanly.

The dud 3.1.0 GitHub release is left in place; it can be deleted separately if you'd rather not have a release with no npm artifact behind it.

HOW TO RELEASE

1. Merge this PR.
2. Cut a 3.1.1 release. Publish to NPM should now succeed.
3. Verify: npm view @elfsquad/authentication version → 3.1.1.

VERIFICATION

• npm run build — compiles clean.
• npm test — 63/63 pass.
• Tested against the real consumer: built this branch, packed it, and installed the tarball into Showroom v2. Full production build, typecheck and lint pass, and its suite is 2226/2227 (the one failure is pre-existing on Showroom's main, confirmed by re-running it against 3.0.0).

FOOTNOTES / CAVEATS

• @elfsquad/configurator bundles its own inlined copy of this package — the OAuth classes and this package's log strings are compiled into configurator/dist/index.js. So bumping a consumer's direct dependency on @elfsquad/authentication is not enough to quiet the logs that come through configurator; configurator needs a rebuild and release of its own. That is follow-up work, not this PR.
• No source change here, so nothing to review behaviourally — this is purely the release-plumbing fix for fix(EL-1547): drop the OAuth library's routine sign-in logs while keeping its failure diagnostics #31.