feat: add envelopes (#2025)

This PR is handles the changes required to support envelopes. The new
envelope editor/signing page will be hidden during release.

The core changes here is to migrate the documents and templates model to
a centralized envelopes model.

Even though Documents and Templates are removed, from the user
perspective they will still exist as we remap envelopes to documents and
templates.

packages/prisma/migrations/20250918070643_remove_template_metadata/migration.sql

@@ -0,0 +1,57 @@
+-- DropForeignKey
+ALTER TABLE "TemplateMeta" DROP CONSTRAINT "TemplateMeta_templateId_fkey";
+
+-- AlterTable
+ALTER TABLE "DocumentMeta" ADD COLUMN     "templateId" INTEGER,
+ALTER COLUMN "documentId" DROP NOT NULL;
+
+-- [CUSTOM_CHANGE] Migrate existing TemplateMeta to DocumentMeta
+INSERT INTO "DocumentMeta" (
+  "id",
+  "subject",
+  "message",
+  "timezone",
+  "password",
+  "dateFormat",
+  "redirectUrl",
+  "signingOrder",
+  "allowDictateNextSigner",
+  "typedSignatureEnabled",
+  "uploadSignatureEnabled",
+  "drawSignatureEnabled",
+  "language",
+  "distributionMethod",
+  "emailSettings",
+  "emailReplyTo",
+  "emailId",
+  "templateId"
+)
+SELECT
+  gen_random_uuid()::text, -- Generate new CUID-like IDs to avoid collisions
+  "subject",
+  "message",
+  "timezone",
+  "password",
+  "dateFormat",
+  "redirectUrl",
+  "signingOrder",
+  "allowDictateNextSigner",
+  "typedSignatureEnabled",
+  "uploadSignatureEnabled",
+  "drawSignatureEnabled",
+  "language",
+  "distributionMethod",
+  "emailSettings",
+  "emailReplyTo",
+  "emailId",
+  "templateId"
+FROM "TemplateMeta";
+
+-- DropTable
+DROP TABLE "TemplateMeta";
+
+-- CreateIndex
+CREATE UNIQUE INDEX "DocumentMeta_templateId_key" ON "DocumentMeta"("templateId");
+
+-- AddForeignKey
+ALTER TABLE "DocumentMeta" ADD CONSTRAINT "DocumentMeta_templateId_fkey" FOREIGN KEY ("templateId") REFERENCES "Template"("id") ON DELETE CASCADE ON UPDATE CASCADE;