fix(seed): use tsconfig.app.json instead of inline --compiler-options

The inline --compiler-options '{"module":"CommonJS",...}' was being
unquoted by the shell when pnpm run db:seed re-spawned ts-node:

  > ts-node --compiler-options {module:CommonJS,esModuleInterop:true,...}

  SyntaxError: Expected property name or '}' in JSON at position 1

Cross-platform quoting of JSON-on-cmdline is a notorious pain.
apps/portal-bff/tsconfig.app.json already declares all the options
we need (module=commonjs, esModuleInterop=true, target=es2021,
moduleResolution=node, types=[node]). Point ts-node at it with -P
and drop the inline JSON entirely.

ts-node --transpile-only ignores the tsconfig's `include`/`exclude`
fields for the file passed explicitly, so the fact that seed.ts is
under prisma/ (not src/) doesn't matter.

package.json

@@ -17,7 +17,7 @@
     "docs:dev": "vitepress dev docs",
     "docs:build": "vitepress build docs",
     "docs:preview": "vitepress preview docs",
-    "db:seed": "ts-node --transpile-only --compiler-options {\"module\":\"CommonJS\",\"esModuleInterop\":true,\"target\":\"ES2020\"} apps/portal-bff/prisma/seed.ts"
+    "db:seed": "ts-node --transpile-only -P apps/portal-bff/tsconfig.app.json apps/portal-bff/prisma/seed.ts"
   },
   "private": true,
   "lint-staged": {