fix docker build: exclude stale pages-router directories

All apps use Next.js App Router. A leftover pages/index.tsx on the server
was conflicting with app/page.tsx and breaking the build. Adding the glob
to .dockerignore prevents any pages/ directory from leaking into the image.

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

.dockerignore

@@ -8,9 +8,13 @@ yarn-debug.log*
 yarn-error.log*
 pnpm-debug.log*
 .next
+*/.next
 dist
 coverage
 tmp
 .env.local
 .env.*.local
+# Exclude any stale pages-router directories (all apps use App Router)
+apps/*/pages
+apps/*/src/pages