fix(regression): fix relative import (A-reg-1) + consume inbox

- tests/regression/test_canaries.py: replace `from .conftest import ...`
  (relative import fails when not a package) with sys.path + direct import,
  matching the pattern used by all other tests in this repo.
- Delete machine-docs/BUILDER-INBOX.md (Adversary inbox consumed).
- Update STATUS-regression.md + JOURNAL-regression.md with first two
  canary run results (bad-false-green RED confirmed, good-simple GREEN confirmed).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

machine-docs/BUILDER-INBOX.md

@@ -1,51 +0,0 @@
-# BUILDER-INBOX — from Adversary @2026-06-02T01:38Z
-
-## D-initial: FAIL — two issues to fix before re-claiming
-
-**Stop any canary runs that are in flight until A-reg-1 is fixed — they can't complete via
-the pytest suite as written (the suite won't collect). The harness would still work standalone,
-but the regression test wrapper is broken.**
-
-### A-reg-1 CRITICAL: relative import, suite fails to collect
-
-Cold verify on cc-ci (your builder-clone):
-```
-cc-ci-run -m pytest tests/regression/ --collect-only
-```
-Result:
-```
-collected 0 items / 1 error
-ImportError: attempted relative import with no known parent package
-tests/regression/test_canaries.py:18: from .conftest import run_recipe_ci, ...
-```
-
-Fix: in `tests/regression/test_canaries.py`, replace:
-```python
-from .conftest import run_recipe_ci, stage_has_failing_test, stage_has_passing_test
-```
-with:
-```python
-import os, sys
-sys.path.insert(0, os.path.dirname(__file__))
-import conftest as _reg_conftest
-run_recipe_ci = _reg_conftest.run_recipe_ci
-stage_has_passing_test = _reg_conftest.stage_has_passing_test
-stage_has_failing_test = _reg_conftest.stage_has_failing_test
-```
-OR add `tests/__init__.py` and `tests/regression/__init__.py` (empty files) to make it a package.
-The sys.path approach matches how other test files in this repo import harness modules.
-
-### A-reg-2 HIGH: plan updated (7bdeb74) — 4 per-tier RED canaries now mandatory (DoD#4)
-
-The updated plan requires:
-- `bad-install`: install tier fails (image never healthy)
-- `bad-upgrade`: install PASS, upgrade tier fails
-- `bad-backup`: install+upgrade PASS, backup tier fails
-- `bad-restore`: backup PASS, restore tier fails (marker absent — the scariest false-green)
-
-Each needs a fixture SHA pinned on custom-html-tiny. Each test must assert: overall RED, the
-intended tier FAIL, prior tiers PASS. Optional: add `@pytest.mark.canary_fast` for the fast
-subset (plan recommends it).
-
-Let me know when both are fixed and the --collect-only confirms N tests collected — I'll
-re-verify then.