Add semver-ci: commit-driven semantic versioning for Gitea Actions

Computes MAJOR.MINOR.PATCH.BUILD from NEW_MAJOR/NEW_MINOR/NEW_PATCH
whole-line tokens in commit messages since the last release tag.
Non-main branches get a BRANCH-SHORTSHA suffix and never release.
Maintains VERSION.md, writes $GITHUB_OUTPUT, and optionally creates
a Gitea release via API.

Includes spec, 67-assertion test, usage guide (docs/semver-ci.md),
and a drop-in Gitea Actions workflow template.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

templates/gitea-workflow-version.yml

@@ -0,0 +1,72 @@
+# .gitea/workflows/version.yml
+#
+# Reusable Gitea Actions workflow that:
+#   - computes the next semantic version from commit-message tokens
+#   - writes VERSION.md in the repo root
+#   - on the main branch, creates a git tag and a Gitea release when
+#     MAJOR, MINOR, or PATCH actually changed
+#
+# Drop this file in at `.gitea/workflows/version.yml` and edit the two
+# values in the `Install semver-ci` step that point at your small-scripts
+# repo if they differ from the defaults.
+#
+# Requirements:
+#   - Gitea Actions enabled for the repo
+#   - A `GITEA_TOKEN` secret with write access to the repo (used for
+#     creating the release). `GITHUB_TOKEN` is also provided automatically
+#     by Gitea Actions and is accepted as a fallback.
+#   - Commit triggers: put NEW_MAJOR, NEW_MINOR, or NEW_PATCH on a line
+#     of its own in a commit message to bump the corresponding part.
+
+name: version
+
+on:
+  push:
+    # Don't re-trigger when we push the tag we just created.
+    tags-ignore:
+      - 'v*'
+
+jobs:
+  version:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout (full history for tags)
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Install semver-ci
+        env:
+          # Edit these two if small-scripts lives elsewhere.
+          SMALL_SCRIPTS_REPO: skynet/small-scripts
+          SMALL_SCRIPTS_REF: main
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: |
+          set -euo pipefail
+          auth=()
+          [ -n "${GITEA_TOKEN:-}" ] && auth=(-H "Authorization: token ${GITEA_TOKEN}")
+          curl -fsSL "${auth[@]}" \
+            "${GITHUB_SERVER_URL%/}/${SMALL_SCRIPTS_REPO}/raw/branch/${SMALL_SCRIPTS_REF}/scripts/semver-ci" \
+            -o /usr/local/bin/semver-ci
+          chmod +x /usr/local/bin/semver-ci
+
+      - name: Compute version & release
+        id: ver
+        run: semver-ci --release
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+
+      - name: Upload VERSION.md
+        uses: actions/upload-artifact@v4
+        with:
+          name: version
+          path: VERSION.md
+          if-no-files-found: warn
+
+      - name: Print summary
+        run: |
+          echo "Version:  ${{ steps.ver.outputs.version }}"
+          echo "Tag:      ${{ steps.ver.outputs.tag }}"
+          echo "Branch:   ${{ steps.ver.outputs.branch }}"
+          echo "Is main:  ${{ steps.ver.outputs.is_main }}"
+          echo "Released: ${{ steps.ver.outputs.released }}"