feature(dashboard): add conversion rate graph

packages/db/prisma/migrations/20250326202409_on_cascade/migration.sql

@@ -0,0 +1,5 @@
+-- DropForeignKey
+ALTER TABLE "clients" DROP CONSTRAINT "clients_organizationId_fkey";
+
+-- AddForeignKey
+ALTER TABLE "clients" ADD CONSTRAINT "clients_organizationId_fkey" FOREIGN KEY ("organizationId") REFERENCES "organizations"("id") ON DELETE CASCADE ON UPDATE CASCADE;

packages/db/prisma/migrations/20250326202444_add_conversion/migration.sql

@@ -0,0 +1,2 @@
+-- AlterEnum
+ALTER TYPE "ChartType" ADD VALUE 'conversion';

packages/db/prisma/schema.prisma

@@ -230,7 +230,7 @@ model Client {
   type           ClientType   @default(write)
   projectId      String?
   project        Project?     @relation(fields: [projectId], references: [id], onDelete: Cascade)
-  organization   Organization @relation(fields: [organizationId], references: [id])
+  organization   Organization @relation(fields: [organizationId], references: [id], onDelete: Cascade)
   organizationId String
 
   createdAt DateTime @default(now())
@@ -257,6 +257,7 @@ enum ChartType {
   map
   funnel
   retention
+  conversion
 }
 
 model Dashboard {