ci: adopt shared @btravstack reusable CI + release workflows

[btravers]

Migrate CI/release to the shared reusable workflows in `btravstack/config` (proven in unthrown).

CI (`.github/workflows/ci.yml`)

• Replaces the common jobs (format, lint, typecheck, knip, test, build, security-audit) with a single call to `btravstack/config/.github/workflows/ci-reusable.yml@main`.
• `changeset: false` (temporal has no changeset job).
• `test-command: "pnpm test -- --coverage --reporter=default --reporter=github-actions"` — matches the old test command.
• knip: used the reusable's built-in knip (the old knip job was plain checkout+setup+`pnpm exec knip`).
• Bespoke jobs kept verbatim: test-integration (unchanged) and bundle-size (`needs: build` → `needs: ci`).

Behavioral deltas (heads-up)

• Node version matrix dropped. The old `test` job ran a 2-entry matrix (default `.node-version` + `22.19.0` engines floor). The reusable runs a single Node version from `.node-version`, so the explicit floor-version test run is no longer exercised in CI.
• Test coverage-artifact upload dropped. The reusable can't upload artifacts; the old `test` job's `upload-artifact` (coverage-report-node-*) is gone. Coverage still runs (`--coverage`), and thresholds still enforce. The integration coverage artifact upload is retained (it's a bespoke job).

Release (`.github/workflows/release.yml`)

• Replaced with a thin call to `btravstack/config/.github/workflows/release-reusable.yml@main`, passing `RELEASE_PAT`.
• The old release used the default `pnpm run version` / `pnpm run release` commands, which are the reusable's defaults, so no `with:` overrides are needed.

`deploy-docs.yml` and `.github/actions/setup` are untouched.

[Copilot]

Pull request overview

This PR migrates this repo’s CI and release pipelines to shared reusable workflows maintained in btravstack/config, reducing local workflow maintenance while keeping the bespoke integration test and bundle-size reporting jobs.

Changes:

• Replace most CI jobs with a single call to btravstack/config/.github/workflows/ci-reusable.yml.
• Replace the release workflow steps with a call to btravstack/config/.github/workflows/release-reusable.yml, passing RELEASE_PAT.
• Update bundle-size to depend on the new ci reusable-workflow job.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
.github/workflows/ci.yml	Switches core CI checks to a shared reusable workflow while retaining integration tests and bundle-size reporting.
.github/workflows/release.yml	Switches releases to a shared reusable workflow, delegating the release implementation to btravstack/config.

Comments suppressed due to low confidence (2)

.github/workflows/release.yml:12

• The reusable workflow is referenced via @main, which is mutable. Pinning to an immutable ref (tag or commit SHA) reduces supply-chain risk and makes releases reproducible.

    if: ${{ github.event.workflow_run.conclusion == 'success' }}
    uses: btravstack/config/.github/workflows/release-reusable.yml@main
    secrets:

.github/workflows/ci.yml:51

• bundle-size now needs: ci (the reusable job), so it will be skipped whenever any CI check fails. Previously it only depended on build, so bundle-size output could still be produced even if lint/tests failed. If you want to preserve that behavior, run bundle-size unconditionally (or at least even when ci fails).

  bundle-size:
    name: Bundle Size
    runs-on: ubuntu-latest
    timeout-minutes: 15
    needs: ci
    steps: