Fix prisma generator provider to prisma-client

The generated TypeScript client in src/generated/prisma was created with
prisma-client provider (new TypeScript-first generator), but schema.prisma
had prisma-client-js. This caused Docker builds to generate files in
node_modules/@prisma/client instead of src/generated/prisma, breaking the
@/generated/prisma/client import.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

prisma/schema.prisma

@@ -1,5 +1,5 @@
 generator client {
-  provider = "prisma-client-js"
+  provider = "prisma-client"
   output   = "../src/generated/prisma"
 }