feat: add svelte web workspace shell

apps/web/src/app/tabs.ts

@@ -0,0 +1,10 @@
+export type WorkspaceTab = {
+  key: string;
+  title: string;
+  route: string;
+};
+
+export function openTab(existing: WorkspaceTab[], next: WorkspaceTab): WorkspaceTab[] {
+  if (existing.some((tab) => tab.key === next.key)) return existing;
+  return [...existing, next];
+}