@@ -0,0 +1,17 @@
+---
+'@objectstack/plugin-security': patch
+---
+
+fix(plugin-security): every member reads and posts comments, and reads the activity history, of the records they can read — the platform baseline `member_default` now grants `sys_comment` (read, create, edit) and `sys_activity` (read)
+
+Clause-②: no — runtime permission behaviour (human-floor security/permission class, ruled by the maintainer), not a published accept-set or public-surface widening
+Metadata-protocol: none
+
+Comments (`enable.feeds`) and the activity timeline (`enable.activities`) are on by default on every object, but no shipped permission set named `sys_comment` or `sys_activity`. A member of an app whose permission sets name only the app's own objects — what `create-objectstack` generates — was refused both (`403` on `GET /api/v1/data/sys_comment` and `GET /api/v1/data/sys_activity`), on records they can read: the record page showed "no permission" for comments and activity, and offered no comment box. An app author no longer needs to grant the two objects by hand.
+
+- **Which rows is unchanged.** The grant opens the two objects; plugin-audit's parent-record gates still decide the rows, so a member reads and posts comments, and reads the history, of exactly the records they can read, and nothing of any other record — a record another user owns under the app's row scope, or a record of an object the member does not read. A member edits the comments they wrote. The grant carries no delete bit (deleting a comment stays the moderation path, through a delete bit an app grants), no export and no view-all or modify-all.
+- **`enable.feeds: false` still closes comments** on that object: creating a comment there, or moving one into it, answers `403 FEEDS_DISABLED`. `enable.activities: false` still writes no activity row for the object.
+- **External members are not reached.** A holder of the `external` organization role does not hold the `everyone` anchor and resolves `external_default` in place of `member_default`, so a portal user still gets comments and activity only through an explicit grant, under the same two gates.
+- **No log noise.** A member's activity read skips the parent objects they cannot read without reading them, so the console header's feed logs no `[Security] Access denied` line per skipped object.
+- An app that already grants the two objects to its members keeps working unchanged: permission sets merge most-permissively, so its own lines (a delete bit included) still apply beside the baseline's.
+- **Lands with the permission-set clone door fix** (`.changeset/30255-clone-inherits-held-grants.md`). This grant first landed alone and was reverted: on a deployment that does not install `@objectstack/plugin-audit`, neither object is registered, and cloning `member_default` answered `422 INVALID_METADATA`. The clone door now copies such a set, so the grant and the fix ship together.
@@ -0,0 +1,13 @@
+---
+'@objectstack/metadata-protocol': patch
+'@objectstack/runtime': patch
+---
+
+fix(runtime, metadata-protocol): the permission-set clone door copies a platform set whose grants name an object this deployment does not install — `member_default` copies into its package's customization pair again on a boot without `@objectstack/plugin-audit`
+
+Clause-②: yes (widening) — `ObjectStackProtocolImplementation.saveMetaItem`'s request gains one optional key, `inheritedGrantObjects`, reachable from `@objectstack/metadata-protocol`'s `.` entry types
+Metadata-protocol: none
+
+- **What failed:** cloning a set through `POST /api/v1/security/permission-sets/:name/clone` answered `422 INVALID_METADATA` when the source grants on an object no package registers here. The commonest source is the platform baseline `member_default`, which grants `sys_comment` and `sys_activity`. `@objectstack/plugin-audit` registers both objects, and it is an optional package: a deployment that does not install it could not clone `member_default` at all.
+- **The rule it now follows:** the save door's unknown-grant refusal (#28990) already leaves alone a grant the set itself already holds, because that grant is not the current write's. A clone's grants are the source's, copied verbatim, so the same holds for a copy. The clone door now tells the save which grant keys the copy inherits (`inheritedGrantObjects`), and the refusal does not judge those.
+- **Still refused:** an unknown object that the save does not say it inherits is this write's grant, and is refused exactly as before. That covers a `/meta` save, a re-save that adds a grant, and a draft's publish. No HTTP door forwards the new key.
@@ -18,7 +18,17 @@ import type { MetadataWriteFace } from './protocol-write-face.js';
  */
 
 /** The request of {@link ObjectStackProtocolImplementation.saveMetaItem}. */
-type SaveMetaItemRequest = { type: string, name: string, item?: any, parentVersion?: string | null, storedParentVersion?: string | null, actor?: string, force?: boolean, mode?: 'draft' | 'publish', packageId?: string | null, source?: string, writeFace?: MetadataWriteFace, surface?: MetadataAuthoringSurface, client?: MetadataAuthoringClient };
+type SaveMetaItemRequest = {
+    type: string, name: string, item?: any, parentVersion?: string | null, storedParentVersion?: string | null, actor?: string, force?: boolean, mode?: 'draft' | 'publish', packageId?: string | null, source?: string, writeFace?: MetadataWriteFace, surface?: MetadataAuthoringSurface, client?: MetadataAuthoringClient,
+    /**
+     * [#30255] The grant keys of a `permission` item that this save copies
+     * verbatim from a set that already holds them — the permission-set clone
+     * door's copy. Not this write's grants, so the unknown-grant refusal does
+     * not judge them, exactly as it does not judge a re-save's grants the set
+     * already holds. Set by server code only; no HTTP door forwards it.
+     */
+    inheritedGrantObjects?: readonly string[],
+};
 
 /** The request of {@link ObjectStackProtocolImplementation.publishMetaItem}. */
 type PublishMetaItemRequest = {
 
@@ -579,6 +579,7 @@ export async function unknownGrantObjectSaveRefusal(
     pending?: 'drafts' | ReadonlySet<string>,
     writeFace?: MetadataWriteFace,
     door: 'save' | 'publish' = 'save',
+    inherited?: readonly string[],
 ): Promise<(Error & { code: 'INVALID_METADATA'; status: 422; issues: MetadataIssueEntry[] }) | undefined> {
     if (singularType !== 'permission') return undefined;
     if (!item || typeof item !== 'object' || Array.isArray(item)) return undefined;
@@ -625,6 +626,14 @@ export async function unknownGrantObjectSaveRefusal(
         : new Set<string>();
     unknown = unknown.filter((key) => !held.has(key));
     if (unknown.length === 0) return undefined;
+    // [#30255] A grant this save copies from a set that already holds it (the
+    // clone door's copy) is the source's, not this save's — the rule above,
+    // for a copy: judged where the source introduced it.
+    if (inherited && inherited.length > 0) {
+        const copied = new Set(inherited);
+        unknown = unknown.filter((key) => !copied.has(key));
+        if (unknown.length === 0) return undefined;
+    }
     // [#29279] What was looked for, as this door looked: a save also counts an
     // object saved here; a draft's publish counts only what goes live with it.
     const looked = door === 'publish'
 
@@ -1575,10 +1575,13 @@ export class ProtocolSaveFacet {
         // already holds and is not judged: a draft-only set has no active row
         // to hold its grants, so judging it refused the pass's own rewrite of
         // a draft whose object draft was gone; the draft is judged at its
-        // publish. See {@link unknownGrantObjectSaveRefusal}.
+        // publish. [#30255] Grants the item copies from a set that already
+        // holds them (`inheritedGrantObjects`, the clone door's copy) are not
+        // this save's either. See {@link unknownGrantObjectSaveRefusal}.
         if (writeSource !== 'migrate-stored') {
             const grantRefusal = await host.unknownGrantObjectSaveRefusal(
                 singularType, request.item, request.name, mode === 'draft' ? 'drafts' : undefined, request.writeFace,
+                undefined, request.inheritedGrantObjects,
             );
             if (grantRefusal) throw grantRefusal;
         }
 
@@ -10306,7 +10306,16 @@ export class ObjectStackProtocolImplementation implements
      *    a set), since the batch promotes as one unit in no type order;
      *  - the set's current definition already grants on it: the grant is not
      *    this write's. A re-save or a restore that keeps it is not judged, and
-     *    neither is an object that has gone since the grant was made.
+     *    neither is an object that has gone since the grant was made;
+     *  - [#30255] the save copies it verbatim from a set that already holds it
+     *    (`inherited`, the request's `inheritedGrantObjects`: the permission-set
+     *    clone door's copy). The grant is the source's, not this write's — the
+     *    rule above, for a copy. A platform set may grant on an object of an
+     *    optional platform plugin this deployment does not install
+     *    (`member_default` on `sys_comment` / `sys_activity`, which
+     *    `@objectstack/plugin-audit` registers): the grant applies to nothing
+     *    here, in the source and in the copy alike, and the copy is what the
+     *    clone door promises.
      *
      * Asked in draft and in publish mode by {@link saveMetaItem} after the
      * schema gate (except a `migrate-stored` re-save, the platform healing
@@ -10327,14 +10336,15 @@ export class ObjectStackProtocolImplementation implements
         pending?: 'drafts' | ReadonlySet<string>,
         writeFace?: MetadataWriteFace,
         door?: 'save' | 'publish',
+        inherited?: readonly string[],
     ): Promise<(Error & { code: 'INVALID_METADATA'; status: 422; issues: MetadataIssueEntry[] }) | undefined> {
         const readEngine = () => this.engine;
         const host: ThisParameterType<typeof unknownGrantObjectSaveRefusal> = {
             get engine() { return readEngine(); },
             listDrafts: (...a) => this.listDrafts(...a),
             readMetaItem: (...a) => this.readMetaItem(...a),
         };
-        return unknownGrantObjectSaveRefusal.call(host, singularType, item, name, pending, writeFace, door);
+        return unknownGrantObjectSaveRefusal.call(host, singularType, item, name, pending, writeFace, door, inherited);
     }
 
     /**
 
@@ -22,9 +22,11 @@
  *  - controls, each saved, published and promoted: a registered object, a
  *    platform object (an RBAC link table), the `'*'` wildcard, an object
  *    stored in this environment, an object drafted in the same package and
- *    published in the same batch (promoted after the set), and a re-save
- *    that keeps a grant the set already holds; a registry that cannot look
- *    an object up refuses nothing.
+ *    published in the same batch (promoted after the set), a re-save
+ *    that keeps a grant the set already holds, and [#30255] a copy whose
+ *    grants a set already holds (`inheritedGrantObjects`, the permission-set
+ *    clone door's copy); a registry that cannot look an object up refuses
+ *    nothing.
  *
  * Each refusal is asserted by its code, its status, its path and the first
  * sentence of its finding, spelled out here.
@@ -363,6 +365,25 @@ describe('[#28990] controls — a grant on an object that exists is not refused'
         expectRefusal(err, 'qa_old', ['qa_typo']);
     });
 
+    it('[#30255] a copy that inherits a grant on an object not registered here (the clone door): saved; a grant the copy adds is still refused', async () => {
+        const { protocol, rows } = makeSession({ objects: ['qa_widget'] });
+
+        const result = await protocol.saveMetaItem({
+            type: 'permission', name: 'qa_copy', item: set('qa_copy', ['qa_widget', 'qa_plugin_object']),
+            inheritedGrantObjects: ['qa_widget', 'qa_plugin_object'],
+        });
+
+        expect(result.success).toBe(true);
+        expect(stored(rows, 'permission', 'qa_copy')).toEqual(['active|-|qa_widget,qa_plugin_object']);
+        // …while an unknown object the copy does not inherit is this save's grant, and refused.
+        const err = await refusalOf(protocol.saveMetaItem({
+            type: 'permission', name: 'qa_copy2', item: set('qa_copy2', ['qa_plugin_object', 'qa_typo']),
+            inheritedGrantObjects: ['qa_plugin_object'],
+        }));
+        expectRefusal(err, 'qa_copy2', ['qa_typo']);
+        expect(stored(rows, 'permission', 'qa_copy2')).toEqual([]);
+    });
+
     it('a registry that cannot look an object up refuses nothing', async () => {
         const { protocol, rows } = makeSession({ looksUpObjects: false });
         expect((await protocol.saveMetaItem({ type: 'permission', name: 'qa_probe', item: set('qa_probe', ['qa_no_such_object']) })).success).toBe(true);
 
@@ -33,8 +33,9 @@
  * ## Who grants the bits
  *
  * The object-level create / read / delete bits come from an ordinary
- * position-distributed set an application ships (as an app grants
- * `sys_comment` today), never from the `everyone`-bound baseline, which
+ * position-distributed set an application ships (as an app grants the
+ * `sys_comment` delete bit; the baseline grants comments' read, create and
+ * edit, never delete), never from the `everyone`-bound baseline, which
  * ADR-0090 D5 keeps free of delete bits. Which shipped set — if any — carries
  * them is an open decision on #22566; the floor pinned here holds whatever set
  * hands the delete bit out.
 
@@ -28,7 +28,7 @@ import { PermissionSetSchema } from '@objectstack/spec/security';
 import type { PermissionSet } from '@objectstack/spec/security';
 import { PermissionEvaluator } from './permission-evaluator.js';
 import { RLSCompiler, RLS_DENY_FILTER } from './rls-compiler.js';
-import { defaultPermissionSets, BETTER_AUTH_MANAGED_OBJECTS } from './objects/default-permission-sets.js';
+import { defaultPermissionSets, BETTER_AUTH_MANAGED_OBJECTS, EXTERNAL_DEFAULT_PERMISSION_SET } from './objects/default-permission-sets.js';
 
 const evaluator = new PermissionEvaluator();
 const MEMBER_DEFAULT = defaultPermissionSets.find((p) => p.name === 'member_default')!;
@@ -267,13 +267,10 @@ describe('[#7344] the personal inbox is readable by a member, scoped to their ow
     expect(rls.compileFilter(policiesFor(object, 'select') as any, {} as any)).toEqual(RLS_DENY_FILTER);
   });
 
-  it('`sys_activity` is deliberately NOT granted — the ruling excludes it', () => {
-    // Named as an explicit negative so a future "while we are here" sweep has to
-    // argue with the ruling rather than quietly widen past it. It is not a
-    // per-user-scoped shape; a separate question if it ever matters.
-    for (const { operation } of AXES) {
-      expect(allows(operation, [MEMBER_DEFAULT], 'sys_activity'), `sys_activity ${operation}`).toBe(false);
-    }
+  it('`sys_activity` rides on its own ruling, not on this one: no `_self` policy scopes it to the caller', () => {
+    // The inbox ruling left it out because it has no `user_id` to scope by. Its
+    // grant (the `[#30108]` block below) is scoped by its parent-record gate, so
+    // no inbox-shaped `_self` carve-out may appear for it.
     const names = (MEMBER_DEFAULT.rowLevelSecurity ?? []).map((p: any) => p.name);
     expect(names).not.toContain('sys_activity_self');
   });
@@ -291,6 +288,60 @@ describe('[#7344] the personal inbox is readable by a member, scoped to their ow
   });
 });
 
+// [#30108 — maintainer ruling 6633054352, 「同意 A」] A record's comments and its
+// activity timeline, for every member who can read the record. The baseline
+// opens the two OBJECTS and nothing more; which rows is plugin-audit's
+// parent-record gates' answer, driven on a real stack in
+// `member-default-feed-grants.integration.test.ts`. What is pinned here is the
+// shape of the opening: the part that would quietly widen if it moved.
+const FEED_OBJECTS = ['sys_comment', 'sys_activity'] as const;
+
+describe('[#30108] the baseline opens comments and activity, and leaves the rows to the parent gates', () => {
+  it('sys_comment: a member reads, posts and edits — and holds no delete bit', () => {
+    expect(allows('find', [MEMBER_DEFAULT], 'sys_comment'), 'read').toBe(true);
+    expect(allows('insert', [MEMBER_DEFAULT], 'sys_comment'), 'create').toBe(true);
+    expect(allows('update', [MEMBER_DEFAULT], 'sys_comment'), 'edit').toBe(true);
+    expect(allows('delete', [MEMBER_DEFAULT], 'sys_comment'), 'delete').toBe(false);
+  });
+
+  it('sys_activity: a member reads — the audit mirror is its only writer', () => {
+    expect(allows('find', [MEMBER_DEFAULT], 'sys_activity'), 'read').toBe(true);
+    for (const operation of ['insert', 'update', 'delete']) {
+      expect(allows(operation, [MEMBER_DEFAULT], 'sys_activity'), operation).toBe(false);
+    }
+  });
+
+  it.each(FEED_OBJECTS)('%s: no read or create row policy of the baseline stands in for the parent gate', (object) => {
+    // A select- or insert-class policy here would answer the gate's question with
+    // a column predicate neither object can answer (no owner or user column, and
+    // a different parent object on every row).
+    expect(policiesFor(object, 'select').map((p: any) => p.name), 'select').toEqual([]);
+    expect(policiesFor(object, 'insert').map((p: any) => p.name), 'insert').toEqual([]);
+  });
+
+  it('sys_comment: an edit stays under the ownership floor — a member edits the comments they wrote', () => {
+    // The moderation carve-out is the DELETE limb only; the edit limb is the
+    // wildcard floor, so a member's edit reaches their own comments alone.
+    expect(policiesFor('sys_comment', 'update').map((p: any) => p.name)).toEqual(['owner_only_writes']);
+  });
+
+  it.each(FEED_OBJECTS)('%s: no export, view-all or modify-all rides along', (object) => {
+    const perm = (MEMBER_DEFAULT.objects as any)[object];
+    expect(perm, `${object} is named`).toBeTruthy();
+    expect(perm.allowDelete ?? false).toBe(false);
+    expect(perm.allowExport ?? false).toBe(false);
+    expect(perm.viewAllRecords ?? false).toBe(false);
+    expect(perm.modifyAllRecords ?? false).toBe(false);
+  });
+
+  it.each(FEED_OBJECTS)('%s: the external baseline does not name it — the grant reaches no external member', (object) => {
+    const external = defaultPermissionSets.find((p) => p.name === EXTERNAL_DEFAULT_PERMISSION_SET)!;
+    expect(external, `${EXTERNAL_DEFAULT_PERMISSION_SET} is shipped`).toBeTruthy();
+    expect(allows('find', [external], object)).toBe(false);
+    expect(Object.keys(external.objects ?? {})).not.toContain(object);
+  });
+});
+
 describe('[#5491] the admin sets keep their wildcards (this is a BASELINE change only)', () => {
   it.each(['admin_full_access', 'organization_admin', 'viewer_readonly'])(
     '%s still carries a `*` entry',