feat(approvals): declare file attachments on approve/reject decisions

Add an optional multi-file `attachments` param to the declared
`approval_approve` / `approval_reject` actions on sys_approval_request. The
console now renders `type:'file'` action params through the shared upload
widget (objectui ADR-0059) and POSTs the resolved `attachments: string[]`, so
a reviewer can attach supporting files to a decision through the generic
declared-action dialog — no bespoke composer.

No service/route change: the decision route already forwards `body.attachments`
to `ApprovalService.decide`, and the `sys_approval_action.attachments` column
(file, multiple) already persists them (#3266/#3274). This just surfaces the
capability as declared metadata so the approvals inbox can retire its
hand-wired attachment composer (objectui#2698).

Contract test pins the new param (type file, multiple, optional).

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016ypkQikZ55oWUHUnMebwXA

Author: claude

packages/plugins/plugin-approvals/src/sys-approval-request.object.test.ts

@@ -91,4 +91,12 @@ describe('sys_approval_request declared actions', () => {
       expect(c.required ?? false).toBe(false);
     }
   });
+
+  it('approve/reject collect optional multi-file decision attachments', () => {
+    for (const name of ['approval_approve', 'approval_reject']) {
+      const att = byName(name).params.find((p: any) => p.name === 'attachments');
+      expect(att, `${name}.attachments`).toMatchObject({ type: 'file', multiple: true });
+      expect(att.required ?? false).toBe(false);
+    }
+  });
 });

packages/plugins/plugin-approvals/src/sys-approval-request.object.ts

@@ -248,6 +248,10 @@ export const SysApprovalRequest = ObjectSchema.create({
       target: '/api/v1/approvals/requests/{id}/approve',
       params: [
         { name: 'comment', label: 'Comment', type: 'textarea', required: false },
+        // Decision attachments (#3266). The console renders `type:'file'` params
+        // through the shared upload widget and POSTs the resolved `attachments:
+        // string[]`; the decision route persists them on `sys_approval_action`.
+        { name: 'attachments', label: 'Attachments', type: 'file', multiple: true, required: false },
       ],
       visible: 'record.status == "pending"',
       locations: ['record_section', 'list_item'],
@@ -263,6 +267,7 @@ export const SysApprovalRequest = ObjectSchema.create({
       target: '/api/v1/approvals/requests/{id}/reject',
       params: [
         { name: 'comment', label: 'Comment', type: 'textarea', required: false },
+        { name: 'attachments', label: 'Attachments', type: 'file', multiple: true, required: false },
       ],
       visible: 'record.status == "pending"',
       confirmText: 'Reject this request? A rejection is final for every approver.',