feat: per-app resource limits, auto-slug, and polished create dialogs

Add per-app memory limit and CPU shares (stored on AppEntity, used by
DeploymentService with fallback to global defaults). JAR upload is now
optional at creation time. Both create modals show the computed slug in
the dialog title and use consistent Cancel-left/Action-right button
layout with inline styles to avoid Modal CSS conflicts.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/utils/slug.ts

@@ -0,0 +1,10 @@
+/** Derive a URL-friendly slug from a display name. */
+export function toSlug(name: string): string {
+  return name
+    .toLowerCase()
+    .trim()
+    .replace(/[^a-z0-9\s-]/g, '')
+    .replace(/[\s]+/g, '-')
+    .replace(/-+/g, '-')
+    .replace(/^-|-$/g, '');
+}