feat(audit): wider coverage — sensitive views, cron, jobs, portal abuse

Builds on the audit infra split (severity/source) by emitting events
from every place a security or operations review would want to see:

Sensitive data views (severity=warning):
- GDPR export download URL issued
- Audit log page opened (watch-the-watchers; first page only)
- CSV export of expenses
- Webhook secret regenerated

Authentication abuse (severity=warning, source=auth):
- Portal sign-in: success + failed-credentials + portal-disabled
- Portal password reset: unknown email + portal-disabled + bad token
- Portal activation: bad/expired token

Inbound webhook hardening:
- Documenso webhook with invalid X-Documenso-Secret now writes
  webhook_failed instead of being silently logged

Background work (source=cron / job):
- New attachWorkerAudit() helper wires every BullMQ worker to emit
  job_failed (severity=error) on .on('failed') and cron_run on
  .on('completed') for any job whose name matches the recurring
  scheduler list. Applied across all 10 workers.

1175/1175 vitest passing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/api/v1/clients/[id]/gdpr-export/[exportId]/route.ts

@@ -3,10 +3,16 @@ import { NextResponse } from 'next/server';
 import { withAuth, withPermission, withRateLimit } from '@/lib/api/helpers';
 import { errorResponse } from '@/lib/errors';
 import { getExportDownloadUrl } from '@/lib/services/gdpr-export.service';
+import { createAuditLog } from '@/lib/audit';
 
 /**
  * Returns a fresh signed URL for an existing GDPR export. Staff use this
  * from the admin UI; the email path embeds its own signed URL.
+ *
+ * Every call writes a `view` audit row at 'warning' severity — GDPR
+ * exports contain the entire personal data of a client and a fresh
+ * presigned URL would let the operator download it; we want a clear
+ * trail of who pulled what when.
  */
 export const GET = withAuth(
   withPermission(
@@ -15,6 +21,19 @@ export const GET = withAuth(
     withRateLimit('exports', async (req, ctx, params) => {
       try {
         const url = await getExportDownloadUrl(params.exportId!, ctx.portId);
+
+        void createAuditLog({
+          userId: ctx.userId,
+          portId: ctx.portId,
+          action: 'view',
+          entityType: 'gdpr_export',
+          entityId: params.exportId!,
+          metadata: { clientId: params.id ?? null, urlIssued: true },
+          ipAddress: ctx.ipAddress,
+          userAgent: ctx.userAgent,
+          severity: 'warning',
+        });
+
         return NextResponse.json({ data: { url } });
       } catch (error) {
         return errorResponse(error);