fix(admin): seed phrases 500 — Prisma 6.19 rejects select+include together

- wallets/seeds: move user relation into nested select (was select+include -> PrismaClientValidationError 500)
- wallets/export-seeds: same fix (CSV export)
- Verified no other top-level select+include conflicts in api routes
- tsc clean

admin-next/src/app/api/wallets/export-seeds/route.ts

@@ -16,8 +16,6 @@ export async function GET(request: NextRequest) {
         address: true,
         derivationPath: true,
         mnemonic: true,
-      },
-      include: {
         user: {
           select: { username: true },
         },

admin-next/src/app/api/wallets/seeds/route.ts

@@ -16,8 +16,6 @@ export async function GET(request: NextRequest) {
         address: true,
         derivationPath: true,
         mnemonic: true,
-      },
-      include: {
         user: {
           select: { username: true },
         },