Docs: ROOT_README shipped-examples table — verify 006-FileUploadWeb row sync

[PurHur]

Problem

#1924 added 005-SessionsWeb to the root README.md shipped-examples table and extended script/check-root-readme-sync.php to fail when examples/README.md mentions 005 but the root table does not.

#1999 / PR #2008 landed 006-FileUploadWeb on master with a row in README.md and examples/README.md, but the drift guard still only checks 005 — contributors can merge stale “opt-in only” wording in the root table while gate flips land (#2009–#2012).

Goal

Extend script/check-root-readme-sync.php (or a sibling checker) so CI fails when:

• examples/README.md documents 006-FileUploadWeb VM/AOT status and root README.md omits the row or shows 🚧 while examples say ✅
• Known stale phrases for 006 gates remain after default-on flips

Scope

Piece	Path
Checker	script/check-root-readme-sync.php — add 006-FileUploadWeb parity like 005 block
Gate	ROOT_README_006_SYNC_GATE=1 in ci-fast (default 0 until checker lands; flip follow-up)
Test	test/unit/RootReadmeSyncTest.php or extend existing sync test
Docs	docs/local-ci-matrix.md one row

Acceptance criteria

php script/check-root-readme-sync.php   # exits 0 on master after implementation
ROOT_README_SYNC_GATE=1 ./script/ci-fast.sh --filter RootReadme

Verification (local / Docker only)

docker run --rm -v "$(pwd):/compiler" -w /compiler php-compiler:22.04-dev \
  php script/check-root-readme-sync.php

No GitHub Actions.

Dependencies

• Examples: 006-FileUploadWeb — multipart $_FILES reference + AOT execute smoke #1999 ✅ — canonical example + README rows
• CI: Default FILE_UPLOAD_WEB_SMOKE_GATE=1 in ci-local after #2008 green #2009 — optional: tighten stale-phrase list after VM gate default-on

Links

• Sibling: Docs: ROOT_README shipped-examples table — add 005-SessionsWeb row #1924 (005 row)
• ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 Phase 4 Polish
• Gate ladder: CI: Default FILE_UPLOAD_WEB_SMOKE_GATE=1 in ci-local after #2008 green #2009–Examples: add 006-FileUploadWeb slice to make examples-aot-smoke #2013

[PurHur]

PM note — batch 106

Root README.md 006-FileUploadWeb row is already synced with post-#2011 / #2012 default-on gates (see line ~115 on master).

Remaining scope for this issue: extend script/check-root-readme-sync.php with a 006 block (like the existing 005 check) so future gate flips cannot leave stale opt-in wording. Optional: ROOT_README_006_SYNC_GATE in ci-fast after checker lands.

Not blocked by #2009–#2013 (all closed/merged).