CI: MINIWEBAPP_SERVE_GATE opt-in for ci-local.sh (ServeTest @group miniwebapp)

[PurHur]

Problem

#470 closed — test/real/ServeTest.php @group miniwebapp PATH_INFO routes pass under phpc serve. #472 stage 2 documents MINIWEBAPP_SERVE_GATE=1, but only script/miniwebapp-gates.sh checks the env var; script/ci-local.sh never reads it.

Full gate contributors expect make test / ci-local to catch serve regressions for 003 without remembering a separate env export.

Goal

When MINIWEBAPP_SERVE_GATE=1 (and loopback bind is allowed — not PHP_COMPILER_SKIP_SERVE_TESTS):

1. ci-local.sh runs PHPUnit with --filter ServeTest limited to @group miniwebapp, or
2. Fails fast if ServeTest miniwebapp cases are skipped while gate is on.

Default remains off until docs promote stage 2; ROADMAP can flip default after one release.

Implementation hints

File	Change
script/ci-local.sh	After existing @group serve block, if MINIWEBAPP_SERVE_GATE=1, run vendor/bin/phpunit --filter ServeTest --group miniwebapp
script/ci-fast.sh	Optional: same under PHP_COMPILER_SKIP_SERVE_TESTS guard
script/miniwebapp-gates.sh	Mark stage 2 [x] when env + ci-local hook exist
test/unit/CiScriptsTest.php	Assert ci-local.sh references MINIWEBAPP_SERVE_GATE

Acceptance criteria

MINIWEBAPP_SERVE_GATE=1 ./script/ci-local.sh --filter ServeTest
# Harness (tar copy if bind-mount empty):
./script/docker-ci-local.sh --filter ServeTest

Serve tests may still skip when loopback bind fails — document alongside #245 / PHP_COMPILER_SKIP_SERVE_TESTS.

No .github/workflows/* required.

Dependencies

• Testing: ServeTest MiniWebApp routes via phpc serve (skipped until #67) #470 — ServeTest routes (closed)
• DevEx: MiniWebApp CI gate ladder (lint → serve → AOT → web-smoke) #472 — gate ladder
• Reference app: MiniWebApp runtime green (lint 0, VM serve, routes) #539 — runtime tracker (closed)

Links

• test/real/ServeTest.php (@group miniwebapp)
• ROADMAP 🗺️ ROADMAP: Compile a small PHP web application (living document) #78

[PurHur]

Merged in #631 — MINIWEBAPP_SERVE_GATE wired into ci-local.sh and ci-fast.sh.