Generate GitHub release notes at build time

[julianhille]

Both release jobs created the GitHub release with softprops/action-gh-release and no body, so a release page showed only the tag and its files.

What changes

• .github/scripts/release-notes.mjs builds the release body from:
  • the ## [<version>] section of the package changelog (CHANGELOG.md for native-v*, packages/wasm/CHANGELOG.md for wasm-v*), with relative links rewritten to blob/<tag>/ URLs so they resolve on the release page;
  • the pull requests merged since the previous tag with the same prefix, with the issues their descriptions close;
  • every contributor in that range, bots excluded;
  • first-time contributors, meaning contributors whose oldest commit on the default branch is part of the release;
  • a compare link to the previous tag.
• The previous tag is the highest semantic version with the same prefix that precedes the released one, so a prerelease compares against the latest stable or prerelease before it. Documentation tags and the other package's tags are never picked. A first release of a prefix gets the changelog section alone.
• Both release jobs run the script right after the version check, so a tag whose version has no changelog section fails before any release or npm publish exists, and pass the result as body_path to the existing release step. The jobs gain pull-requests: read.
• npm run test:release-notes runs the script's node --test suite (22 tests over a fake API) and is part of the linting workflow.
• The Release Tags sections of both development docs describe the generated notes and how to reproduce them locally for a published tag.
• Changed entries in both changelogs.

Verified

Run locally against the real native-v7.1.0 and wasm-v1.1.0 tags; both produce the expected sections with 28 pull requests and their closed issues. The missing-section case exits with code 1 and a clear message.

Closes #962

[read-the-docs-community]

Documentation build overview

📚 MuhammaraJS | 🛠️ Build #35005485 | 📁 Comparing 106458b against latest (7e56040)

  🔍 Preview build  

4 files changed

± development.html
± api/type-declarations.html
± recipe/encryption.html
± recipe/reference.html

[read-the-docs-community]

Documentation build overview

📚 MuhammaraJS WASM | 🛠️ Build #35005486 | 📁 Comparing 106458b against latest (7e56040)

  🔍 Preview build  

2 files changed

± browser-examples.html
± development.html

[julianhille]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Merged develop and resolved both changelog conflicts, preserving the entries from each branch. Merge commit: 106458b.