ci: standardize release presentation and baseline dependencies (#7)

Author: ryanbarlow97

.github/workflows/maven-release.yml

@@ -137,5 +137,26 @@ jobs:
           sha256sum --check SHA256SUMS
           flags=()
           if [[ "$TAG" == *-* ]]; then flags+=(--prerelease); fi
+          gh api --method POST "repos/$GH_REPO/releases/generate-notes" \
+            -f tag_name="$TAG" --jq .body > "$RUNNER_TEMP/release-changes.md"
+          python3 - <<'PY'
+          import os, re
+          from pathlib import Path
+          from urllib.parse import quote
+          temp = Path(os.environ['RUNNER_TEMP'])
+          changes = (temp / 'release-changes.md').read_text().strip()
+          changes = re.sub(r"^## What's Changed\s*", '', changes)
+          changes = re.sub(r'^(#{1,5}) ', r'\1# ', changes, flags=re.MULTILINE)
+          lines = ['## Changes', '', changes or 'Initial release.', '', '## Downloads', '']
+          assets = sorted([*Path('.').glob('*.jar'), *Path('.').glob('*.tar.gz')])
+          assets += [Path('SHA256SUMS'), Path('build.json')]
+          base = f"https://github.com/{os.environ['GH_REPO']}/releases/download/{quote(os.environ['TAG'], safe='')}/"
+          for asset in assets:
+              if not asset.is_file():
+                  raise SystemExit(f'Missing release asset: {asset}')
+              description = {'SHA256SUMS': ' — SHA-256 checksums.', 'build.json': ' — Build metadata.'}.get(asset.name, '')
+              lines.append(f'- [`{asset.name}`]({base}{quote(asset.name)}){description}')
+          (temp / 'release-notes.md').write_text('\n'.join(lines) + '\n')
+          PY
           gh release create "$TAG" ./*.jar SHA256SUMS build.json \
-            --verify-tag --draft --title "$TAG" --generate-notes "${flags[@]}"
+            --verify-tag --draft --title "$TAG" --notes-file "$RUNNER_TEMP/release-notes.md" "${flags[@]}"