chore(changeset): declare the ADR-0087 disposition for #4914

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PiRUoQkTSBBmpyXBY3cVn2

Author: claude

.changeset/plugin-manifest-loading-removed.md

@@ -4,6 +4,8 @@
 
 refactor(spec)!: remove `manifest.loading` — a whole plugin loading block nothing read, including a sandbox that isolated nothing (#4914)
 
+<!-- adr-0087: registered plugin-manifest-loading-retired -->
+
 `manifest.loading` and the entire `PluginLoadingConfig` block behind it are
 removed under ADR-0049 enforce-or-remove (maintainer ruling 2026-08-04). The
 block declared a complete plugin loading policy — `strategy`, `preload`,