Add GitHub UI action for validated release tags

.github/workflows/create-release-tag.yml

@@ -0,0 +1,143 @@
+name: Create OreSpawn release tag
+run-name: Create OreSpawn tag from ${{ inputs.release_ref }}
+
+on:
+  workflow_dispatch:
+    inputs:
+      release_ref:
+        description: MMD target branch or commit to tag, for example master-1.10.2.
+        required: true
+        default: master-1.10.2
+        type: string
+      confirm_version:
+        description: Exact four-component version declared by the target, for example 4.0.8.110021.
+        required: true
+        type: string
+
+permissions:
+  actions: read
+  contents: write
+
+concurrency:
+  group: orespawn-create-tag-${{ inputs.confirm_version }}
+  cancel-in-progress: false
+
+jobs:
+  create-release-tag:
+    name: Validate candidate and create tag
+    if: github.repository == 'MinecraftModDevelopmentMods/OreSpawn'
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Check out selected release candidate
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          ref: ${{ inputs.release_ref }}
+          fetch-depth: 0
+
+      - name: Validate target, version, and prior CI
+        id: validate
+        env:
+          GH_TOKEN: ${{ github.token }}
+          CONFIRM_VERSION: ${{ inputs.confirm_version }}
+        run: |
+          set -euo pipefail
+
+          value() { sed -n "s/^$1=//p" gradle.properties; }
+          release_version="$(value mod_version)"
+          minecraft_version="$(value minecraft_version)"
+          loader_name="$(value loader_name)"
+          loader_code="$(value loader_code)"
+
+          for required in release_version minecraft_version loader_name loader_code; do
+            if [[ -z "${!required}" ]]; then
+              echo "Selected ref is missing required release metadata: $required" >&2
+              exit 1
+            fi
+          done
+
+          IFS=. read -r mc_major mc_minor mc_patch extra <<<"$minecraft_version"
+          if [[ -n "${extra:-}" || -z "${mc_major:-}" || -z "${mc_minor:-}" ]]; then
+            echo "Invalid minecraft_version=$minecraft_version" >&2
+            exit 1
+          fi
+          mc_patch="${mc_patch:-0}"
+          if [[ ! "$mc_major" =~ ^[0-9]+$ || ! "$mc_minor" =~ ^[0-9]+$ || ! "$mc_patch" =~ ^[0-9]+$ ]]; then
+            echo "Invalid minecraft_version=$minecraft_version" >&2
+            exit 1
+          fi
+          case "$loader_name:$loader_code" in
+            forge:1|neoforge:2) ;;
+            *) echo "Invalid loader metadata $loader_name/$loader_code" >&2; exit 1 ;;
+          esac
+
+          printf -v minor_padded '%02d' "$((10#$mc_minor))"
+          printf -v patch_padded '%02d' "$((10#$mc_patch))"
+          target_suffix="${mc_major}${minor_padded}${patch_padded}${loader_code}"
+          if [[ ! "$release_version" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.${target_suffix}$ ]]; then
+            echo "mod_version $release_version does not match $minecraft_version $loader_name target $target_suffix" >&2
+            exit 1
+          fi
+          if [[ "$CONFIRM_VERSION" != "$release_version" ]]; then
+            echo "confirm_version must equal $release_version" >&2
+            exit 1
+          fi
+          if [[ ! -f .github/workflows/release-on-tag.yml ]]; then
+            echo "Selected target has not adopted the validated tag workflow" >&2
+            exit 1
+          fi
+
+          release_sha="$(git rev-parse HEAD)"
+          successful_ci="$(gh api \
+            "repos/$GITHUB_REPOSITORY/commits/$release_sha/check-runs?per_page=100" \
+            --jq '[.check_runs[] | select(.name == "Build, test, and audit" and .conclusion == "success")] | length')"
+          if [[ "$successful_ci" -lt 1 ]]; then
+            echo "The selected commit has no successful Build, test, and audit check" >&2
+            exit 1
+          fi
+          if gh api "repos/$GITHUB_REPOSITORY/git/ref/tags/$release_version" >/dev/null 2>&1; then
+            echo "Tag $release_version already exists" >&2
+            exit 1
+          fi
+
+          echo "release_version=$release_version" >> "$GITHUB_OUTPUT"
+          echo "release_sha=$release_sha" >> "$GITHUB_OUTPUT"
+
+      - name: Create the validated release tag
+        env:
+          GH_TOKEN: ${{ github.token }}
+          RELEASE_VERSION: ${{ steps.validate.outputs.release_version }}
+          RELEASE_SHA: ${{ steps.validate.outputs.release_sha }}
+        run: |
+          set -euo pipefail
+          gh api --method POST "repos/$GITHUB_REPOSITORY/git/refs" \
+            -f ref="refs/tags/$RELEASE_VERSION" \
+            -f sha="$RELEASE_SHA" >/dev/null
+
+          created_sha="$(gh api "repos/$GITHUB_REPOSITORY/git/ref/tags/$RELEASE_VERSION" --jq '.object.sha')"
+          if [[ "$created_sha" != "$RELEASE_SHA" ]]; then
+            echo "Created tag resolved to $created_sha instead of $RELEASE_SHA" >&2
+            exit 1
+          fi
+
+      - name: Show the manual publication step
+        env:
+          RELEASE_VERSION: ${{ steps.validate.outputs.release_version }}
+          RELEASE_SHA: ${{ steps.validate.outputs.release_sha }}
+          RELEASE_WORKFLOW_URL: https://github.com/${{ github.repository }}/actions/workflows/deploy-release.yml
+        run: |
+          {
+            echo "## Release tag created"
+            echo
+            echo "Tag \`$RELEASE_VERSION\` now points to validated commit \`$RELEASE_SHA\`."
+            echo
+            echo "**Nothing has been published.**"
+            echo
+            echo "To continue, open [Deploy OreSpawn release]($RELEASE_WORKFLOW_URL), select **Run workflow**, and enter:"
+            echo
+            echo "- mode: \`publish\`"
+            echo "- release_ref: \`$RELEASE_VERSION\`"
+            echo "- curseforge_channel: \`release\`, \`beta\`, or \`alpha\`"
+            echo "- confirm_version: \`$RELEASE_VERSION\`"
+          } >> "$GITHUB_STEP_SUMMARY"