test: release.test.ts keeps only cast's own surfaces; changelog line

The machinery halves — notes extraction, arming, monotonicity, the drill
gate, the old workflow's shape pins — go where their subjects went:
ceremony's test/ carries changelog.test.sh, changelog-armed.test.sh,
changelog-monotonic.test.sh and drill-recorded.test.sh at the 0.1.0 pin
(upstream equivalence verified per ceremony#13's rule), and the pinned
actions enforce them in ci.yml. What stays, retargeted at what can still
break HERE: the caller stubs' load-bearing shape (one push key, the
package-json backend, CONSUMERS.md's same-tag rule across all six
ceremony references), the artifact hook's install contract (asset name,
staged layout, no tests, own toolchain), the drill doctrine in cast's own
docs (independence + candidate-ref pinning, now against drills/README.md),
and the installer's three channels, untouched. 1374 -> 418 lines;
722 tests green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,12 @@ actually cutting it, and this file starts there.
 
 ## Unreleased
 
+### Changed
+
+- The release flow and labels automation now run heavy-duty/ceremony's shared
+  machinery at 0.1.0; the prebuilt-asset build moves to the release-artifact
+  hook (heavy-duty/ceremony#15)
+
 ## 0.2.0 — 2026-07-21
 
 ### Added