fix(plugins): preserve unavailable release failures

tests/unit/hosted-admission.test.ts

@@ -122,6 +122,33 @@ describe('MarketplaceHostedAdmissionResolver', () => {
     expect(error).toMatchObject({ code: 'plugin_runtime_stale', status: 409, retryable: false });
   });
 
+  it.each([
+    'plugin_release_not_ready',
+    'plugin_client_incompatible',
+  ])('preserves an explicit unavailable Release as plugin_release_unavailable (%s)', async (reason) => {
+    const marketplace = {
+      resolve: vi.fn(async () => resolved({
+        action: 'unavailable',
+        releaseAdmissionId: null,
+        reason,
+      })),
+    } as unknown as Pick<MarketplacePackageClientPort, 'resolve'>;
+    const unavailableResolver = new MarketplaceHostedAdmissionResolver({
+      packageStore: { getInstalledRelease: vi.fn(async () => installed()) } as unknown as Pick<PluginPackageStore, 'getInstalledRelease'>,
+      marketplace,
+      makeloreVersion: '1.2.4',
+    });
+
+    await expect(unavailableResolver.resolve({
+      pluginId: PLUGIN_ID,
+      workerSnapshot: { requestId: REQUEST_ID, pluginReleaseId: RELEASE_ID },
+    })).rejects.toMatchObject({
+      code: 'plugin_release_unavailable',
+      status: 409,
+      retryable: false,
+    });
+  });
+
   it('projects an account change as a typed non-retryable worker failure', async () => {
     const { resolver, resolve } = resolverFixture();
     resolve.mockRejectedValueOnce({ code: 'marketplace_account_changed' });