chore(changeset): carry the BREAKING banner on the install answer narrowing

A non-protocol breaking change ships patch and keeps its banner; the
line follows the spelling the other narrowing changesets use.

Co-authored-by: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L6bhgVugtCCwBs98FeR27P

Author: claude

.changeset/30464-install-response-bare-row.md

@@ -7,6 +7,8 @@ fix(spec): `PackageInstallResponseSchema` declares the installed row that `POST
 Clause-②: yes (narrowing)
 Metadata-protocol: none
 
+**BREAKING** accept-set narrowing at the install answer contract (`@objectstack/spec`): `PackageInstallResponseSchema` refuses the `{ package }` wrapper it accepted, and `PackageInstallResponse['data']` no longer declares `package`, `dependencyResolution`, `namespaceConflicts` or `message`.
+
 `POST /api/v1/packages` answers `{ success: true, data: <row> }` with status `201`, where the row is the `InstalledPackage` the registry recorded. `PackageInstallResponseSchema` (the output `PackageApiContracts.installPackage` binds) declared `data: { package, dependencyResolution?, namespaceConflicts?, message? }` instead. No surface sent that wrapper, so code written against the contract read `data.package` and got `undefined`. The first-party client already followed the wire: `client.packages.install` resolves to `InstalledPackage`.
 
 - **FROM** `data: { package: InstalledPackage, dependencyResolution?, namespaceConflicts?, message? }` **TO** `data: InstalledPackage`. The name, the type names (`PackageInstallResponse`, `PackageInstallResponseParsed`) and the binding are unchanged. The server's answer is unchanged.