fix: use client ID instead of email for UAT client upsert

The seed script was using schema.clients.email as the onConflictDoUpdate
target, but the database does not have a unique constraint on clients.email.
Since UAT clients use deterministic IDs (e.g., uat-alpha-client-001),
switch to using schema.clients.id as the upsert target.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/db/src/seed.ts

@@ -417,7 +417,7 @@ async function seedUatClients(db: ReturnType<typeof drizzle>) {
         address: null,
       })
       .onConflictDoUpdate({
-        target: schema.clients.email,
+        target: schema.clients.id,
         set: { name: uat.name },
       });