ci(node): add node release workflow

[inyellowbus]

Add .github/workflows/node-release.yml — CI workflow triggered on node/v* tags:

• Builds Docker image from src/Dockerfile
• Pushes to ghcr.io/rsquad/ton-rust-node/node (version tag + latest for stable + sha-*)
• Creates GitHub Release (Latest for stable, Pre-release for RC/alpha/beta)

[Copilot]

Pull request overview

This PR adds a new GitHub Actions workflow for automated Node release management. It's triggered on node/v* tags and performs two main tasks: building and pushing a Docker image to GHCR, and creating a corresponding GitHub Release. The workflow distinguishes between stable releases (marked as latest) and pre-releases (rc, alpha, beta) with appropriate tagging and draft status.

Changes:

• Adds Docker image build and push on tag push events with semantic versioning and SHA-based tags
• Creates GitHub Releases with appropriate pre-release and latest designations based on version identifiers
• Implements concurrency controls to prevent duplicate runs

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[Copilot]

The github.event.head_commit context is not available when the workflow is triggered by a tag push event. This will result in an empty or null value being passed as GIT_COMMIT_DATE to the Docker build. Consider using github.event.repository.pushed_at or obtaining the commit timestamp through a separate git command after checkout (e.g., git log -1 --format=%cI).