chore(release): switch to per-package release PRs for version in title (LAB-888)

[27Bslash6]

Problem

release-please's generated release PR title is uninformative: chore: release main (#83) — no version, no package. Since cachekit-ts is squash-merge-only with squash_merge_commit_title=PR_TITLE, that title becomes the permanent commit header on main when the release PR merges.

Root cause (verified against release-please source, not just docs)

The combined/manifest PR title uses MANIFEST_PULL_REQUEST_TITLE_PATTERN = 'chore: release ${branch}' (release-please src/manifest.ts). The Merge plugin (src/plugins/merge.ts) only populates ${component}/${version} from a candidate release at path === '.':

if (candidate.path === '.') {
  rootRelease = candidate;
}
...
title: PullRequestTitle.ofComponentTargetBranchVersion(
  rootRelease?.pullRequest.title.component,
  this.targetBranch,
  rootRelease?.pullRequest.title.version,
  ...
)

None of this repo's 3 packages (packages/cachekit, packages/cachekit-core-ts, packages/cachekit-core-wasm) live at root path ., so rootRelease is always null — meaning ${component}/${version} render empty regardless of pull-request-title-pattern or group-pull-request-title-pattern configuration, and regardless of how many packages bump in a cycle. Setting either title-pattern option to include those tokens would not have fixed anything.

Fix

"separate-pull-requests": true in release-please-config.json. Each package now gets its own release PR (only for packages with releasable changes — usually just cachekit per cycle), using release-please's per-component default title pattern (chore${scope}: release${component} ${version}), which does populate component/version since each per-package candidate carries its own. Example: chore(main): release cachekit 0.1.5.

Verified

• Matches pr-title-lint.yml's conventional-commit regex.
• Release detection in .github/workflows/release-please.yml reads per-path outputs (packages/cachekit--release_created etc.) — unaffected by combined vs. separate PRs.
• No linked-versions plugin configured, so per-package independent versioning (already the case per .release-please-manifest.json) is unaffected.
• Noted but out of scope: the Assign release PR step keys off steps.release.outputs.pr (first PR only) — in the common one-package-bumps-per-cycle case this is unaffected; if 2+ packages ever bump in the same cycle, only one of the resulting PRs gets auto-assigned. Not touching this here — config-file-only scope per LAB-888.

Docs gate

No docs needed: internal release-automation config only, no user-facing SDK surface.

LAB-888

Summary by CodeRabbit

• Chores
  • Updated release management configuration to create separate pull requests for individual releases.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: 78ad4d1d-f148-4ac3-9129-7f63fe978101

📥 Commits

Reviewing files that changed from the base of the PR and between 555dd99 and 2dcdb13.

📒 Files selected for processing (1)

• release-please-config.json

---

Walkthrough

The release-please configuration now enables separate pull requests through the separate-pull-requests setting.

Changes

Release Please configuration

Layer / File(s)	Summary
Enable separate release pull requests release-please-config.json	Adds "separate-pull-requests": true to the release-please configuration.

Estimated code review effort: 1 (Trivial) | ~2 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes enabling per-package release PRs to include version info, which matches the config change.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch lab-888-release-please-title-version

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