FIXED - Make adding a portfolio project simpler and actually saveable

- Fix critical bug: TabsContent unmounted inactive panels, so the project
  form only submitted the active tab's fields and could never save; add an
  opt-in forceMount that keeps panels mounted (hidden) and use it on all
  four project-form tabs
- Make Sections and Assets optional: a project saves with just Basics and
  Localized Content; new projects start with no sections/assets, and the
  last one can now be removed
- Update wizard progress so empty sections/assets steps count as complete
- Update save hint copy and step labels to reflect the optional steps
- Correct .claude/launch.json dev port to 3014
- Update portfolio-form-progress tests for the optional-steps behaviour

components/ui/tabs.tsx

@@ -98,22 +98,28 @@ function TabsTrigger({
 
 type TabsContentProps = React.HTMLAttributes<HTMLDivElement> & {
   value: string;
+  // Keep the panel mounted while inactive (hidden via `hidden`) so its form
+  // fields still submit. Use for tabbed forms that share one submit button.
+  forceMount?: boolean;
 };
 
 function TabsContent({
   className,
   value,
   children,
+  forceMount = false,
   ...props
 }: TabsContentProps) {
   const { value: activeValue } = useTabsContext();
+  const isActive = activeValue === value;
 
-  if (activeValue !== value) {
+  if (!isActive && !forceMount) {
     return null;
   }
 
   return (
     <div
+      hidden={!isActive}
       className={cn(
         "mt-6 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-0",
         className,