test: registry dispatch + per-test ghost-guard (PR-1)

[grantdh]

Summary

Replaces manual main() dispatch in test_correctness.c, test_chaos.c, and test_device_api.c with a TESTS[] registry array. Each TESTS[i].fn() is bracketed by a pre/post counter delta — the dispatcher abort()s and names the offending test if a registered test produces zero counter increment, catching ghost tests (silent fall-off-the-end with no PASS/FAIL/CHECK invocation).

abort() not assert() so the guard survives -DNDEBUG release builds.

Files

• tests/test_registry.h: 9-line header, no link dependency
• tests/test_correctness.c: 66 TestCase entries (PASS/FAIL globals)
• tests/test_chaos.c: 18 TestCase entries (PASS/FAIL globals)
• tests/test_device_api.c: 11 TestCase entries (CHECK macro + checks_run counter per §2(b'); 4 void-wrappers around 2 parameterized helpers per §2(b''))
• tests/test_ghost_detection.c: meta-test, does NOT link against libapplebottom; deliberately includes a ghost test, returns 42 on success (Makefile target inverts the exit code)
• tests/README.md: PR-1 documentation (how to add tests, what guard catches/doesn't, coverage status across PR-1 / PR-1.5 / orphan)
• Makefile: test-ghost-detection target wired into both test: and ci-local: aggregates; CI_REPORT.txt gains test-ghost-detection: PASS

Acceptance

• AC#1–9 all green (per-file counts: 66/66, 18/18, 11/11)
• 74 PASS / 0 FAIL pre and post, prefix-stripped outcome diff empty
• Wall-time delta: 6.710s → 6.787s = +1.1% (within ±5%)
• 0 → 0 compiler warnings
• 4 of 5 CI gates green (make test, make test-ghost-detection, make ci-local, make verify-symbols); make test-asan pre-existing breakage on main, not regressed (see below)

Out of scope

• test_precision.c and test_convergence.c → PR-1.5 (single-main / monolithic; need decomposition strategy)
• Orphan files (test_rectangular.c, test_original_rectangular.c, test_rectangle_debug.c) — not in any build target; separate delete-or-wire-up decision

Pre-existing issue (not regressed)

make test-asan fails on main with the same unable to open output file build/apple_bottom.o error after make clean wipes BUILD; the test-asan target lacks the | $(BUILD) order-only prerequisite. Orthogonal Makefile bug.

Spec friction (in-spirit equivalence verified, polish deferred)

• AC#3 strict diff non-empty due to new [N/M] test_name ... registry header prefix; outcome equivalence verified via prefix-stripped awk + raw counts (74 PASS / 0 FAIL pre and post). Spec revision history will be updated to note prefix-stripping is the canonical AC#3 verification.
• AC#6 awk-grep returns 0 against post-migration files (main() no longer has bare test_*(); lines); legitimate semantic is "pre-migration baseline (66/18/11) vs post-migration registry-entries (66/18/11)" — holds.