ci: integrate release-please action (#116)

* ci: integrate release-please action

Adopt release-please for automated versioning and releases, modeled on
the hub-seeder setup and adapted for Python/Poetry/PyPI.

- Add release-please-config.json (release-type: python, v-prefixed tags,
  bump-minor-pre-major) and bootstrap .release-please-manifest.json to
  the current version 0.2.16 to align with existing v* tags.
- Add release.yml that runs release-please on pushes to main and, once a
  release is created, builds the package, publishes to PyPI via trusted
  publishing, and deploys the Sphinx docs.
- Remove publish.yml and sphinx.yml; their tag-triggered jobs are folded
  into release.yml since tags created with GITHUB_TOKEN do not trigger
  separate workflows.

* ci: gate publish job explicitly on releases_created

Author: tada5hi

.github/workflows/publish.yml

@@ -0,0 +1,86 @@
+name: Release
+
+on:
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  release-please:
+    runs-on: ubuntu-latest
+    outputs:
+      releases_created: ${{ steps.release.outputs.releases_created }}
+    steps:
+      - name: Release Please
+        id: release
+        uses: googleapis/release-please-action@v5
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+  build:
+    runs-on: ubuntu-latest
+    needs: release-please
+    if: needs.release-please.outputs.releases_created == 'true'
+    steps:
+      - uses: actions/checkout@v6
+      - name: Set up Poetry
+        uses: ./.github/actions/setup-poetry
+      - name: Install dependencies
+        run: poetry install
+      - name: Build package
+        run: poetry build --no-interaction
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v7
+        with:
+          path: dist/
+          name: package-dist
+
+  publish:
+    runs-on: ubuntu-latest
+    needs: [release-please, build]
+    if: needs.release-please.outputs.releases_created == 'true'
+    environment: pypi
+    permissions:
+      id-token: write
+    steps:
+      - name: Download build artifact
+        uses: actions/download-artifact@v8
+        with:
+          path: ${{ github.workspace }}/dist/
+          name: package-dist
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+
+  docs:
+    runs-on: ubuntu-latest
+    needs: release-please
+    if: needs.release-please.outputs.releases_created == 'true'
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+      - name: Set up Poetry
+        uses: ./.github/actions/setup-poetry
+      - name: Install dependencies
+        run: poetry install --with docs
+      - name: Build HTML
+        run: poetry run make -C docs/ html
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v7
+        with:
+          name: html-docs
+          path: docs/_build/html
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v4
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: docs/_build/html

.github/workflows/release.yml

@@ -0,0 +1,3 @@
+{
+  ".": "0.2.16"
+}

.github/workflows/sphinx.yml

@@ -0,0 +1,9 @@
+{
+  "release-type": "python",
+  "include-component-in-tag": false,
+  "include-v-in-tag": true,
+  "bump-minor-pre-major": true,
+  "packages": {
+    ".": {}
+  }
+}