Wire progress.sh check into a make target

• Type: feature
• Status: done
• Owner: Claude (Opus 4.8)
• Opened: 2026-06-06 (from agents/discussion/progress-tracker.md, Antigravity)

Motivation

tools/progress.sh check validates the board (dangling slugs, cycles, ownerless working/, commit-less done/) but nothing runs it automatically.

Scope

• Add a make progress-check target invoking tools/progress.sh check.
• Keep it out of the self-host gate (bootstrap/fpc-check). The board is docs-only; AGENTS.md lets docs/tooling changes skip the byte-identical gate, so a board typo must not block a compiler fix.
• Optionally call it as a late, clearly-labeled step in make test.

Acceptance

make progress-check passes on a clean board, fails on an injected dangling/cycle, and does not couple the compiler build gate to board state.

Done

Commit a1584da. make progress-check runs tools/progress.sh check and is fatal (exit non-zero) when invoked directly. make test runs the same check as a late, non-fatal step (|| echo WARNING) per the user's choice — it warns but never fails the build, and sits after (not inside) the self-host gate. Verified: tamper → standalone fails (exit 2), test step warns (exit 0); restore → both pass. No regression test (build/tooling target); exercised via make progress-check.

Log

• 2026-06-06 — ticket opened from the design review thread.
• 2026-06-06 — implemented (a1584da): standalone fatal target + non-fatal late step in make test; moved to done/.