feat(06-01): install packages + extend schema + generate migration

- installed signature_pad, @react-email/render, @react-email/components
- added signingTokens table (jti pk, documentId, expiresAt, usedAt)
- added auditEvents table with auditEventTypeEnum (6 event types)
- added signedFilePath, pdfHash, signedAt columns to documents table
- generated and applied migration 0005_signing_flow.sql

teressa-copeland-homes/package.json

@@ -18,6 +18,8 @@
     "@cantoo/pdf-lib": "^2.6.3",
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/utilities": "^3.2.2",
+    "@react-email/components": "^1.0.10",
+    "@react-email/render": "^2.0.4",
     "@vercel/blob": "^2.3.1",
     "adm-zip": "^0.5.16",
     "bcryptjs": "^3.0.3",
@@ -30,6 +32,7 @@
     "react": "19.2.4",
     "react-dom": "19.2.4",
     "react-pdf": "^10.4.1",
+    "signature_pad": "^5.1.3",
     "zod": "^4.3.6"
   },
   "jest": {