fix: repair js release pipeline for monorepo layout

.github/workflows/js.yml

@@ -409,7 +409,7 @@ jobs:
 
       - name: Merge multiple changesets
         if: steps.check_changesets.outputs.has_changesets == 'true' && steps.check_changesets.outputs.changeset_count > 1
-        run: node scripts/merge-changesets.mjs
+        run: node scripts/merge-changesets.mjs --working-dir js
 
       - name: Version packages and commit to main
         if: steps.check_changesets.outputs.has_changesets == 'true'
@@ -425,7 +425,7 @@ jobs:
         if: steps.publish.outputs.published == 'true'
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: node scripts/create-github-release.mjs --release-version "${{ steps.publish.outputs.published_version }}" --repository "${{ github.repository }}" --prefix "js-" --changelog-file "js/CHANGELOG.md"
+        run: node scripts/create-github-release.mjs --release-version "${{ steps.publish.outputs.published_version }}" --repository "${{ github.repository }}" --prefix "js-" --changelog-file "js/CHANGELOG.md" --badge-type "npm" --package-name "start-command"
 
       - name: Format GitHub release notes
         if: steps.publish.outputs.published == 'true'
@@ -478,7 +478,7 @@ jobs:
         if: steps.publish.outputs.published == 'true'
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: node scripts/create-github-release.mjs --release-version "${{ steps.publish.outputs.published_version }}" --repository "${{ github.repository }}" --prefix "js-" --changelog-file "js/CHANGELOG.md"
+        run: node scripts/create-github-release.mjs --release-version "${{ steps.publish.outputs.published_version }}" --repository "${{ github.repository }}" --prefix "js-" --changelog-file "js/CHANGELOG.md" --badge-type "npm" --package-name "start-command"
 
       - name: Format GitHub release notes
         if: steps.publish.outputs.published == 'true'

docs/case-studies/issue-116/README.md

@@ -0,0 +1,37 @@
+# Case Study: Issue #116 - Fix all CI/CD issues after language-prefixed releases
+
+## Summary
+
+Issue #116 reported that the JavaScript release pipeline was still failing
+after the issue-114 fixes shipped. The reported failed run was
+[CI run 25263794761](https://github.com/link-foundation/start/actions/runs/25263794761).
+The user also asked us to confirm both JavaScript and Rust GitHub Releases
+have:
+
+- Language prefixes in both release **tags** (`js-v<version>` / `rust-v<version>`).
+- Language prefixes in both release **titles** (`[JavaScript] <version>` /
+  `[Rust] <version>`).
+- Specific exact-version package badges (npm for JS, crates.io for Rust).
+
+## Contents
+
+- [requirements.md](requirements.md) - requirements extracted from the issue.
+- [timeline.md](timeline.md) - ordered reconstruction of events.
+- [root-cause.md](root-cause.md) - evidence-backed root cause for the failed run.
+- [solutions.md](solutions.md) - considered fixes and selected implementation.
+- [ci-logs/](ci-logs/) - relevant downloaded GitHub Actions log excerpts.
+
+## High-level findings
+
+| Area              | Finding                                                                                                                              | Fix                                                                                                                                                              |
+| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| JS release        | `scripts/merge-changesets.mjs` had hardcoded `PACKAGE_NAME = 'my-package'` and `CHANGESET_DIR = '.changeset'` (template placeholders, not the repo paths). | Read `name` from `<workingDir>/package.json` and use `<workingDir>/.changeset`; accept `--working-dir <dir>`.                                                    |
+| JS workflow      | `js.yml` invoked `node scripts/merge-changesets.mjs` from the repo root, so it tried to scan `./.changeset` (which does not exist in this monorepo).        | Pass `--working-dir js` to the script in the auto-release job.                                                                                                   |
+| JS release notes | Only the Rust `create-github-release.mjs` invocation passed `--badge-type "crates" --package-name`; the JS invocation skipped the badge entirely.           | Pass `--badge-type "npm" --package-name "start-command"` to both JS `create-github-release.mjs` invocations (auto-release and instant-release).                  |
+| Tags & titles    | `releaseTag()` and `releaseName()` already produce `js-v<version>` / `[JavaScript] <version>` and `rust-v<version>` / `[Rust] <version>` correctly.        | No code change needed; verified by existing `js/test/release-name.mjs` cases.                                                                                    |
+
+## See also
+
+- Issue: https://github.com/link-foundation/start/issues/116
+- Pull request: https://github.com/link-foundation/start/pull/117
+- Predecessor issue: https://github.com/link-foundation/start/issues/114