CI: Add GitHub Actions workflow for PHPUnit (VM, compliance, real, AOT)

[PurHur]

Context

CircleCI badge exists in README; there is no in-repo GitHub Actions workflow. Project rule asks to run tests before commit—automation should match make test / script/ci-local.sh.

Goal

Run the PHPUnit suites on every push/PR.

Tasks

• Workflow: install PHP 8.x + extensions, composer install, script/install-llvm9.sh
• Run vendor/bin/phpunit (or split jobs: unit/compliance vs AOT with LLVM cache)
• Mark AOT suite as continue-on-error or skip when LLVM unavailable (mirror AotTest::isLlvmReady())
• Upload .llvm or cache LLVM tarball between runs
• Badge in README

Acceptance criteria

Green CI on master for VM + compliance + real-world suites; AOT runs when toolchain present.

References

• phpunit.xml.dist test suites
• test/aot/AotTest.php

[PurHur]

Historical note (backlog architect)

This issue is closed — GHA exists for optional remote signal.

Canonical verification for contributors and harness hosts:

./script/ci-local.sh
# or:
make test-docker
./script/docker-ci-local.sh

GHA sets PHP_COMPILER_SKIP_SERVE_TESTS=1; local/Docker CI must not (#234, #245). See #78 ROADMAP “Local CI is canonical.”

[PurHur]

De-duplication (batch 12)

Workflow exists and issue is closed. For contributors on Runforge/harness hosts:

• Canonical gate: script/ci-local.sh or ./script/docker-ci-local.sh (see Docs: Local CI matrix (host, Docker, GHA skips) in README #245)
• Serve tests: GHA sets PHP_COMPILER_SKIP_SERVE_TESTS=1; Docker/local must not export that variable (Testing: Run HTTP serve integration tests in Docker local CI #234, Testing: ServeTest POST form submission via phpc serve #248)
• JIT guard: CI: ci-local.sh fail when LLVM present but JIT compliance 100% skipped #250 until CI: Run JIT compliance tests in CI (fix LLVM skip in PHPUnit) #98 root cause fixed

Do not open duplicate “add CI” issues — extend #245 / #98 instead.

[PurHur]

CI de-dupe (batch 14): Closed as optional cloud mirror. Canonical CI for this repo is local: script/ci-local.sh, make test-docker, make test-harness (#272).

Track contributor-facing matrix in #245; JIT must execute when LLVM present (#98, guard #250 ✅). Do not reopen GHA work unless explicitly requested — harness/Runforge has no Actions dependency.