Fix release workflow tag handling and bump crate to 0.3.1

[elasticdotventures]

Summary

• fix GHCR push failure by lowercasing the image repository name
• drive release tagging from Cargo.toml version and validate pushed tag matches crate version
• keep container tags aligned by pushing vX.Y.Z, X.Y.Z, and latest
• bump crate version to 0.3.1 and sync server.json
• update version bump hook to include server.json in automated bumps

Validation

• cargo check --locked

Context

Fixes failing Actions run/job: https://github.com/PromptExecution/rust-cargo-docs-rag-mcp/actions/runs/21807304139/job/62912761753

[Copilot]

Pull request overview

This PR fixes the project’s release/publish automation by deriving release tags from the crate version, ensuring GHCR image names are lowercased, and bumping the crate to 0.3.1 while keeping auxiliary metadata in sync.

Changes:

• Bump crate version to 0.3.1 and update related metadata (Cargo.lock, server.json, README).
• Update release workflow to compute tags from Cargo.toml version, validate pushed tag matches, and publish multiple container tags (vX.Y.Z, X.Y.Z, latest).
• Extend the version bump hook to also update and stage server.json.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
server.json	Sync server metadata version + OCI identifier tag to 0.3.1.
scripts/set-version.sh	Update server.json version and OCI tag during automated version bumps.
cog.toml	Stage server.json in post-bump git add hook.
README.md	Update example Docker pull tag to v0.3.1.
Cargo.toml	Bump crate version to 0.3.1.
Cargo.lock	Sync lockfile entry version to 0.3.1.
.github/workflows/release-and-publish.yml	Lowercase GHCR repo name, derive release tag from Cargo.toml, validate tag/version alignment, and push aligned image tags.

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[Copilot]

Now that the workflow derives release_tag (and can run via workflow_dispatch), the later asset-upload steps should explicitly target the same tag. Currently those steps use softprops/action-gh-release without tag_name, which defaults to github.ref and can attach assets to the wrong release (or fail) when not running on a tag ref. Consider passing tag_name: ${{ steps.version.outputs.release_tag }} to the upload steps (or using the create_release step outputs) to keep all release operations aligned.