@@ -0,0 +1,18 @@
+---
+'@objectstack/cli': minor
+---
+
+fix(cli)!: `docs/nav-target` judges the navigation each package body contributes on a multi-package artifact
+
+Clause-②: no (narrowing) — on a multi-package `composeStacks(…, { manifest: 'preserve' })` artifact, a `type: 'doc'` item in a package body's `navigationContributions`, whose `doc` or `book` names nothing the artifact carries, built clean before and is now refused by `os build`, `os validate` and `os lint` (`docs/nav-target`).
+Metadata-protocol: narrowed
+
+<!-- adr-0087: not-required (no-migration-prescription) No key of any schema is added, removed, renamed or re-shaped, and no export or type of the package's public surface changes: the build-time docs lint now reaches the navigation contributions a package body carries, judging them by the rule it already applies to a single-package stack's contributions. A refused item is fixed in the contribution; there is nothing for a migration to rewrite. -->
+
+**BREAKING** accept-set narrowing in the build-time docs lint (`os build`, `os validate`, `os lint`).
+
+- **Before.** The `docs/nav-target` check read `navigationContributions` off the artifact's top-level manifest only. On a multi-package `preserve` artifact that manifest is the owner package's copy, so a contribution from any other package was never judged: a dead `doc` or `book` target built clean and degraded at runtime.
+- **Now.** When the stack carries `packages[]`, the check reads each package body's `navigationContributions` (the owner's included, judged once); otherwise the top-level manifest's. A contributed `doc` item resolves against every doc the artifact carries, and a `book` item against the declared books and package ids, as a single-package contribution always did.
+- **Unchanged.** A stack with no `packages[]` is judged exactly as before.
+
+**The remedy.** For a refused item, name a doc in `src/docs/*.md` or a declared book (a package id is its own implicit book), or remove the item from the contribution. The refusal message names the nearest match.
@@ -104,6 +104,25 @@ describe('docs/nav-target — a doc nav item must open something this package ha
     expect(issues.map((i) => [i.rule, i.path])).toEqual([['docs/nav-target', 'apps/crm_app/navigation/nav_page']]);
   });
 
+  it('judges the doc entries every package body contributes on a multi-package `preserve` artifact, each once', () => {
+    // The real composer: the top-level manifest is the last package's (the owner's) copy, so a
+    // non-owner package's contributions sit only in its body.
+    const contribution = (id: string, doc: string) => [{ app: 'setup', items: [{ id, type: 'doc', doc }] }];
+    const composed = (svc: unknown, crm?: unknown) => JSON.parse(JSON.stringify(composeStacks([
+      defineStack({ manifest: { id: 'com.example.svc', name: 'svc', namespace: 'svc', version: '1.0.0', type: 'app', navigationContributions: svc } } as never, { strict: false }),
+      defineStack({ manifest: { id: 'com.example.crm', name: 'crm', namespace: 'crm', version: '1.0.0', type: 'app', ...(crm ? { navigationContributions: crm } : {}) } } as never, { strict: false }),
+    ], { manifest: 'preserve' }))) as Record<string, unknown>;
+    const nonOwner = composed(contribution('nav_svc_help', 'ghost_doc'));
+    expect((nonOwner.manifest as Record<string, unknown>).navigationContributions).toBeUndefined();
+    expect(lintDocNavTargets(composed(contribution('nav_svc_help', 'crm_intro')), DOCS)).toEqual([]);
+    expect(lintDocNavTargets(nonOwner, DOCS).map((i) => [i.rule, i.path]))
+      .toEqual([['docs/nav-target', 'apps/setup/navigation/nav_svc_help']]);
+    // The owner contributes too: its top-level copy is not judged a second time.
+    const both = composed(contribution('nav_svc_help', 'ghost_doc'), contribution('nav_crm_help', 'ghost_doc'));
+    expect(lintDocNavTargets(both, DOCS).map((i) => i.path))
+      .toEqual(['apps/setup/navigation/nav_svc_help', 'apps/setup/navigation/nav_crm_help']);
+  });
+
   it('resolves a book declared on a package body, and that package id as its implicit book', () => {
     expect(lintDocNavTargets({
       packages: [{ manifest: { id: 'com.example.help', books: [{ name: 'help_centre', groups: [] }] } }],
 
@@ -1110,7 +1110,9 @@ export function lintMetadataEmbeds(
  *
  * Walked: every app's `navigation` and `areas[].navigation` (children
  * included) — the top level's apps, or each package body's when the top level
- * carries none — and the items of `manifest.navigationContributions`.
+ * carries none — and the items of `navigationContributions`: each package
+ * body's when the stack carries `packages[]`, otherwise the top-level
+ * manifest's.
  *
  * ## What resolves
  *
@@ -1194,7 +1196,15 @@ export function lintDocNavTargets(stack: Record<string, unknown>, docNames: Read
   // A package may also CONTRIBUTE a doc entry into an app it does not own
   // (ADR-0029 D7). The entry opens this package's docs, so it is judged here,
   // against this package's set, under the name of the app it lands in.
-  const contributions = (stack.manifest as { navigationContributions?: unknown } | undefined)?.navigationContributions;
+  // On a multi-package `preserve` artifact each package's contributions sit in
+  // its body, and the top-level manifest is only the owner's copy: each body's
+  // when the stack carries `packages[]` (so the owner's are judged once),
+  // otherwise the top-level manifest's — `collectNavGroupInputs`' rule, over
+  // the same `artifactPackages` walk as the books and apps above.
+  const bodies = artifactPackages(stack);
+  const contributions = (bodies.length > 0
+    ? bodies.flatMap(({ body }) => (Array.isArray(body.navigationContributions) ? body.navigationContributions : []))
+    : (stack.manifest as { navigationContributions?: unknown } | undefined)?.navigationContributions);
   if (Array.isArray(contributions)) {
     for (const c of contributions as AnyRec[]) {
       check(c?.items, typeof c?.app === 'string' ? c.app : '(unnamed)');