Add document approval workflow

Introduce a complete approval system for document publishing. Document
versions can now require approval from selected reviewers before being
published, with automatic publishing once all approvers have approved.

- Add approval quorum and decision tables with backfill migration
- Implement request approval, approve, and reject flows with electronic
  signature support for approve decisions
- Add employee approvals page with dedicated tab and pending approvals view
- Add changelog field to publish and request approval flows
- Pre-select previous version's approvers in the publish dialog
- Show quorum approvers in document list with 100 approver hard limit
- Expose approval workflow through GraphQL, MCP, and CLI
- Remove legacy default approvers feature entirely
- Add comprehensive e2e test coverage for approval workflows

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

packages/emails/src/DocumentApproval.tsx

@@ -0,0 +1,36 @@
+import { Button, Section, Text } from '@react-email/components';
+import * as React from 'react';
+import EmailLayout, { bodyText, button, buttonContainer, footerText } from './components/EmailLayout';
+
+export const DocumentApproval = () => {
+  return (
+    <EmailLayout subject={'Action Required – Please review and approve {{.DocumentName}}'}>
+      <Text style={bodyText}>
+        You're receiving this message because <strong>{'{{.OrganizationName}}'}</strong> has requested your approval on the document <strong>{'{{.DocumentName}}'}</strong>.
+      </Text>
+      <Text style={bodyText}>
+        Please take a moment to review the document and approve or reject it by clicking the button below:
+      </Text>
+
+      <Section style={buttonContainer}>
+        <Button style={button} href={'{{.ApprovalUrl}}'}>
+          Review and Approve
+        </Button>
+      </Section>
+
+      <Text style={bodyText}>
+        If you have any questions, please contact your security team.
+      </Text>
+
+      <Text style={footerText}>
+        This process is managed securely by Probo, acting as the compliance partner on behalf of <strong>{'{{.OrganizationName}}'}</strong>.
+        Thank you for your prompt attention to this matter.
+      </Text>
+      <Text style={footerText}>
+        Best regards,
+      </Text>
+    </EmailLayout>
+  );
+};
+
+export default DocumentApproval;

packages/emails/src/ElectronicSignatureCertificate.tsx

@@ -8,10 +8,10 @@ import EmailLayout, {
 export const ElectronicSignatureCertificate = () => {
   return (
     <EmailLayout
-      subject={`Your signed ${"{{.DocumentType}}"} — Certificate of Completion`}
+      subject={`Your signed ${"{{.DocumentName}}"} — Certificate of Completion`}
     >
       <Text style={bodyText}>
-        Your <strong>{"{{.DocumentType}}"}</strong> has been signed
+        Your <strong>{"{{.DocumentName}}"}</strong> has been signed
         electronically. A Certificate of Completion is attached to this email
         as a PDF document.
       </Text>