DevEx: phpc doctor --selfhost — dedicated gate ladder for North Star 2

[PurHur]

Problem

phpc doctor --gates lists dozens of env vars; self-host probes are mixed with MiniWebApp / examples gates. #1865 added make north-star2-verify, but there is no phpc doctor --selfhost (or --gates-selfhost) that prints only:

• BOOTSTRAP_LIB_SPINE_* / BOOTSTRAP_M3_* / BOOTSTRAP_LOOP_*
• NORTH_STAR2_VERIFY_GATE, SELFHOST_SPINE_*_SYNC_GATE
• One-line “run next” commands (make north-star2-verify, bootstrap-selfhost-helloworld-probe.sh)

Presenters and harness operators grep docs instead of a single CLI surface.

Goal

./phpc doctor --selfhost
# or: ./phpc doctor --gates --filter selfhost

Output sections:

1. Inventory — bootstrap-inventory.php --check status hint
2. M2 spine — count 603/606, coverage sync gate state
3. M3 emit — partial vs strict probe env vars (Self-host M3: Native emit for compiler compile-smoke fixture (post-#1493) #1937, CI: BOOTSTRAP_M3_COMPILE_SMOKE_STRICT_GATE opt-in in ci-local after #1937 #1968)
4. Presenter — make north-star2-verify + NORTH_STAR2_VERIFY_GATE default (DevEx: north-star2-verify presenter + M3 compile-smoke emit link #2046 when flipped)
5. LLVM — whether ci_llvm_dir is ready (mirror doctor LLVM probe)

Scope

• lib/Doctor.php — new flag or filter; no behavior change to default doctor
• test/unit/PhpcDoctorTest.php — assert section headers and key env names
• docs/bootstrap-selfhost.md, docs/GETTING-STARTED.md — link new flag

Out of scope: implementing M3 emit (#1937).

Acceptance criteria

./phpc doctor --selfhost | grep -E 'BOOTSTRAP_|NORTH_STAR2|SELFHOST_SPINE'
docker run --rm -v "$(pwd):/compiler" -w /compiler php-compiler:22.04-dev ./phpc doctor --selfhost

No GitHub Actions required.

Dependencies

• DevEx: make north-star2-verify presenter gate (self-host M0–M4) #1865 ✅ presenter script · optional DevEx: north-star2-verify presenter + M3 compile-smoke emit link #2046 for default-on ci-fast wording

Links

• Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 · DevEx: phpc doctor --gates lists 005-SessionsWeb ladder (#1887–#1894) #1903 sessions gate ladder pattern