fix(rest): the 501 on /meta/:type/:name/published now states its true post-#8278 condition (#10160)

Both `/published` arities share one message literal (a `for` loop registers the
same handler for both routes), reached only after the runtime-published overlay
consult finds nothing. Post-#8278 that 501 no longer means "this kernel cannot
answer /published" -- it means "nothing is runtime-published for this item, and
this kernel has no code/package store" -- so reword it to say that instead of the
stale "metadata.getPublished() is not available in this kernel".

Per the maintainer ruling on #8297 (2026-08-20, minimal action): getPublished
stays optional on IMetadataService (no contract movement), and the documented
existing-but-never-published -> 200 fallback semantics are untouched.

Status code, error.code, and routing order are byte-identical -- only the
message prose changed. meta-published-overlay.test.ts SS8 (which pins the exact
response body) is updated to match; SS9 (the 200-from-overlay arm) is untouched.


Claude-Session: https://claude.ai/code/session_016gcKVsiywU9CcS96S5t9qD

Co-authored-by: Claude <noreply@anthropic.com>

Author: Jack Q

.changeset/rest-published-501-message.md

@@ -0,0 +1,12 @@
+---
+"@objectstack/rest": patch
+---
+
+Reworded the `501 NOT_IMPLEMENTED` message on `GET /meta/:type/:name/published` (and its
+compound-name arity) to state its true post-#8278 condition. Since #8278 put the
+runtime-published overlay consult ahead of this arm, the 501 no longer means "this kernel
+cannot answer `/published`" — it means "nothing is runtime-published for this item, and
+this kernel has no code/package store" (i.e. `metadata.getPublished()` is unavailable).
+The old message ("metadata.getPublished() is not available in this kernel") overstated
+that condition. Status code, `error.code`, and routing order are unchanged — only the
+message text changed.

packages/rest/src/meta-published-overlay.test.ts

@@ -425,7 +425,10 @@ describe('[#8278] what the overlay consult must NOT change', () => {
         expect(res.body).toEqual({
             error: {
                 code: 'NOT_IMPLEMENTED',
-                message: 'metadata.getPublished() is not available in this kernel',
+                // [#8297] Reworded to state the TRUE post-#8278 condition — this
+                // arm is reached only after a null overlay consult, so it no
+                // longer means "this kernel cannot answer /published" at all.
+                message: 'Nothing is runtime-published for this item, and this kernel has no code/package store (metadata.getPublished() is not available).',
             },
         });
     }, 60_000);

packages/rest/src/rest-server.ts

@@ -6253,10 +6253,20 @@ export class RestServer {
 
                         const svc = await this.resolveMetadataService(environmentId, req);
                         if (typeof (svc as any)?.getPublished !== 'function') {
+                            // [#8297] Reached ONLY when the overlay consult above
+                            // found nothing (a null `layered.overlay`) — so this is
+                            // no longer "this kernel cannot answer /published" (the
+                            // pre-#8278 reading); it is the narrower, rarer
+                            // condition the message below actually states: nothing
+                            // is runtime-published for this item, AND this kernel's
+                            // metadata slot has no code/package store to fall back
+                            // to (`getPublished` is optional on `IMetadataService`
+                            // and unimplemented here). Status, `code`, and routing
+                            // order are unchanged — only the prose was stale.
                             res.status(501).json({
                                 error: {
                                     code: 'NOT_IMPLEMENTED',
-                                    message: 'metadata.getPublished() is not available in this kernel',
+                                    message: 'Nothing is runtime-published for this item, and this kernel has no code/package store (metadata.getPublished() is not available).',
                                 },
                             });
                             return;