PF-3329: migrate to pnpm 10 + Node 24 + GitHub Packages

[genisd]

Summary

Migrates @gynzy/ember-cli-ifa to:

• pnpm@10.33.4 (was yarn)
• Node 24 (was 10.* || >= 12)
• GitHub Packages registry (was npm.gynzy.net)
• util.workflowJavascriptPackage() from lib-jsonnet (was handwritten publish-pr.yml / publish-tag.yml + ci/npm.sh + ci/publish.sh)

This PR also bootstraps this repo to lib-jsonnet for the first time (no prior .github.jsonnet / .github/jsonnet/).

Dependency on lib-jsonnet#257

This PR pulls lib-jsonnet from PR adopted-ember-addons#257 (packageManager='pnpm' support in workflowJavascriptPackage). After lib-jsonnet#257 merges to prod, a follow-up should run sh .github/jsonnet/pull-upstream-and-rebuild.sh (without PR_NUMBER) to repin to prod.

Discovery results

Item	Value
Default branch	main
Repo visibility	PUBLIC → isPublicFork=true (runs on ubuntu-latest)
Prior package manager	yarn (yarn.lock, .yarnrc)
Version bump	0.10.0 → 0.11.0 (minor +1, patch reset)
lint command	pnpm run lint (npm-run-all lint:* → eslint)
test command	pnpm run test (npm-run-all lint:* test:* → eslint + ember test + ember try:each)
build command	pnpm run build (ember build --environment=production)
Services needed	none (no docker services)
Tag-publish trigger	yes (covered by workflowJavascriptPackage's tag handling)

Generated pipelines

workflowJavascriptPackage produces three workflows:

• misc.yml — verifyJsonnet (jsonnet ↔ YAML consistency check)
• pr.yml — pnpm-publish-preview + test job
• publish-prod.yml — pnpm-publish on push to main

Verified the generated YAML contains:

• no npm.gynzy.net
• no setGynzyNpmToken
• node:24 everywhere
• pnpm (no yarn)

Removed legacy

• .github/workflows/publish-pr.yml
• .github/workflows/publish-tag.yml

ci/npm.sh and ci/publish.sh are now dead code (only referenced by the removed workflows) but are left in place to keep this PR minimal — they can be cleaned up in a follow-up.

Preserved pipelines

None beyond the helper output — there were no non-helper pipelines (pulumi etc.) in this repo.

Open Questions

1. pnpm run build fails locally under pnpm. ember build --environment=production throws To use these addons, your app needs ember-auto-import >= 2: ember-cli-fastboot-testing. This is a known ember + pnpm hoisting issue (yarn's hoisted layout hid it; pnpm's isolated layout exposes it). Mitigated in this PR by passing buildSteps=[] to workflowJavascriptPackage — the build step is for the dummy test app, and the addon's .npmignore excludes /dist so publish doesn't need it. Test job also omits build. If you want CI to run ember build, add node-linker=hoisted to .npmrc (or upgrade ember-auto-import) in a follow-up.

2. pnpm run test requires a browser (Chrome) — the node:24 container does not have one. The existing CI (legacy publish-pr.yml/publish-tag.yml) never ran tests; the previous test runner was Travis (.travis.yml), which is no longer wired up. The new test job will fail on test:ember / test:ember-compatibility until a Chrome-equipped image (or xvfb + chromium install step) is wired up. Lint will still pass via the same pnpm run test.

3. .travis.yml is dead (no Travis integration). Not removed in this PR to keep the change minimal.

Test plan

• misc workflow (verifyJsonnet) passes — proves jsonnet generated YAML is consistent
• pnpm-publish-preview job publishes a PR-tagged version to GitHub Packages
• Decide on the open questions before merging (test job Chrome, build hoisting)
• After lib-jsonnet#257 lands in prod, follow up with sh .github/jsonnet/pull-upstream-and-rebuild.sh to repin