ci: switch to CalVer for versioning

Author: DoNotResuscitate

.github/workflows/main.yml

@@ -60,7 +60,7 @@ jobs:
         id: deployment
         uses: actions/deploy-pages@v4
 
-  # Semantic release job
+  # CalVer release job
   release-on-push:
     permissions:
       contents: write
@@ -71,13 +71,68 @@ jobs:
         uses: actions/checkout@v5
         with:
           fetch-depth: 0
-          persist-credentials: false
-      - name: Semantic Release
-        uses: cycjimmy/semantic-release-action@v4
-        with:
-          branches: main
-          extra_plugins: |
-            conventional-changelog-conventionalcommits@8.0.0
-            @semantic-release/commit-analyzer@10.0.1
+      - name: Create CalVer tag
+        id: calver
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          git fetch --tags
+
+          existing_tag="$(git tag --points-at HEAD | grep -E '^[0-9]{2}\.[0-9]{2}\.[0-9]+$' | head -n 1 || true)"
+          if [[ -n "${existing_tag}" ]]; then
+            echo "tag=${existing_tag}" >> "$GITHUB_OUTPUT"
+            echo "created=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+
+          base="$(TZ=UTC date +%y.%m)"
+          latest_for_month="$(git tag -l "${base}.*" | grep -E "^${base//./\\.}\.[0-9]+$" | sort -V | tail -n 1 || true)"
+
+          if [[ -z "${latest_for_month}" ]]; then
+            tag="${base}.0"
+          else
+            sequence="${latest_for_month##*.}"
+            tag="${base}.$((sequence + 1))"
+          fi
+
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git tag -a "${tag}" -m "Release ${tag}"
+          git push origin "${tag}"
+
+          echo "tag=${tag}" >> "$GITHUB_OUTPUT"
+          echo "created=true" >> "$GITHUB_OUTPUT"
+      - name: Publish GitHub release
+        uses: actions/github-script@v8
         env:
-          GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN || github.token }}
+          RELEASE_TAG: ${{ steps.calver.outputs.tag }}
+        with:
+          script: |
+            const tag = process.env.RELEASE_TAG;
+            const { owner, repo } = context.repo;
+
+            try {
+              const existing = await github.rest.repos.getReleaseByTag({
+                owner,
+                repo,
+                tag,
+              });
+              core.info(`Release already exists for ${tag}: ${existing.data.html_url}`);
+              return;
+            } catch (error) {
+              if (error.status !== 404) {
+                throw error;
+              }
+            }
+
+            const release = await github.rest.repos.createRelease({
+              owner,
+              repo,
+              tag_name: tag,
+              name: `Release ${tag}`,
+              generate_release_notes: true,
+            });
+
+            core.info(`Created release ${release.data.html_url}`);

.releaserc

@@ -1,2 +1,4 @@
 # apocryphal-frontier
 Apocryphal Frontier System Reference Document
+
+Releases use CalVer tags in the format `YY.0M.MICRO`, where `MICRO` starts at `0` and increments for each release in the same UTC month.