fix(regression): correct SHAs for bad-backup/bad-restore (A-reg-3) + consume inbox

Both compose.yml uploads had empty files due to a bash encoding bug.
Fixed via Python API upload; new SHAs:
- regression-bad-backup: cd52b3a (backupbot.backup.path=/nonexistent-path-cc-ci-canary-bad)
- regression-bad-restore: 7e03499 (backup targets .backup-data subdir + command creates it)

Adversary confirmed bad-install ✓ and bad-upgrade ✓ from run artifacts.

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

machine-docs/BUILDER-INBOX.md

@@ -1,49 +0,0 @@
-# BUILDER-INBOX — from Adversary @2026-06-02T02:00Z
-
-## A-reg-3 CRITICAL: bad-backup and bad-restore fixtures have empty compose.yml
-
-Both `regression-bad-backup` and `regression-bad-restore` branches in custom-html have
-**entirely empty compose.yml** (the whole file was deleted). This breaks the upgrade tier
-for both canaries — chaos upgrade deploys an empty compose → no service → upgrade fails.
-
-Cold verification:
-```bash
-ssh cc-ci 'cd /root/.abra/recipes/custom-html && git diff origin/main..origin/regression-bad-backup -- compose.yml'
-```
-Shows: everything from `version: "3.8"` to the end deleted, only a blank line remains.
-
-**Run artifact evidence:**
-- `regression-bad-backup-1`: `install=pass, upgrade=fail, backup=skip`
-  - Expected: `install=pass, upgrade=pass, backup=fail`
-- `regression-bad-restore`: never reached backup/restore (same root cause)
-
-**`_assert_red_at_tier` for bad-backup fails**: `results["backup"]="skip"` ≠ "fail"
-
-## Fix required
-
-For `regression-bad-backup` on custom-html: compose.yml must be the FULL valid compose
-(copy of main), with ONLY this label changed:
-```yaml
-- "backupbot.backup.path=/usr/share/nginx/html"
-```
-→ changed to:
-```yaml
-- "backupbot.backup.path=/nonexistent-path-cc-ci-canary-bad"
-```
-
-For `regression-bad-restore` on custom-html: compose.yml must be the FULL valid compose
-(copy of main), with the backupbot path pointed at a SUBDIR that doesn't contain ci-marker.txt:
-```yaml
-- "backupbot.backup.path=/usr/share/nginx/html/.backup-data"
-```
-(This dir is either empty or doesn't contain ci-marker.txt → backup succeeds but doesn't
-capture the marker → restore doesn't recover it → test_restore_returns_state fails: "mutated"
-not "original")
-
-## Status
-
-- bad-install: ✓ CONFIRMED working (install=fail, upgrade=na)
-- bad-upgrade: ✓ CONFIRMED working (install=pass, upgrade=fail)
-- bad-backup: ✗ BROKEN (fix needed)
-- bad-restore: ✗ BROKEN (fix needed, blocked on backup fix)
-- good-significant: still needs re-run (upgrade flakiness check)

tests/regression/test_canaries.py

@@ -128,7 +128,7 @@ _BAD_BACKUP = {
     "src": "recipe-maintainers/custom-html",
     # Pin: regression-bad-backup @ 2026-06-02 — backupbot.backup.path=/nonexistent-path-cc-ci-canary-bad
     # `abra app backup create` fails → backup tier RED. install+upgrade still PASS.
-    "ref": "e1e3c5fc5e2bd414600b6d3a9f2266566415ff34",
+    "ref": "cd52b3a02d2cc1a73ec598766cc1bf1c62b465ec",
     "expected_green": False,
     "stages": "install,upgrade,backup",
     "failing_tier": "backup",
@@ -144,7 +144,7 @@ _BAD_RESTORE = {
     # Pin: regression-bad-restore @ 2026-06-02 — backup captures /usr/share/nginx/html/.backup-data/
     # (a subdir NOT containing ci-marker.txt). Restore restores the subdir → marker stays "mutated"
     # → test_restore_returns_state FAILS → restore tier RED. install+upgrade+backup PASS.
-    "ref": "5a481cc1f6b2a46279b8e0eca09ca7cb4dc6f25d",
+    "ref": "7e03499ff17b343b622b510efcfc44add9651065",
     "expected_green": False,
     "stages": "install,upgrade,backup,restore,custom",
     "failing_tier": "restore",