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

tests/unit/portfolio-form-progress.test.ts

@@ -117,10 +117,29 @@ describe("getPortfolioWizardProgress", () => {
     expect(getFirstIncompleteWizardStep(progress)).toBe("content");
   });
 
-  it("sections/assets steps require at least one ready entry", () => {
+  it("treats sections/assets as optional: empty steps are complete and the project is saveable", () => {
     const noEntries = getPortfolioWizardProgress({ ...completeInput, sections: [], assets: [] });
-    expect(noEntries.find((s) => s.key === "sections")?.complete).toBe(false);
-    expect(noEntries.find((s) => s.key === "assets")?.complete).toBe(false);
+    expect(noEntries.find((s) => s.key === "sections")?.complete).toBe(true);
+    expect(noEntries.find((s) => s.key === "assets")?.complete).toBe(true);
+    // Basics + content only is enough to save.
+    expect(getFirstIncompleteWizardStep(noEntries)).toBeNull();
+  });
+
+  it("shows an optional summary when no sections/assets are added", () => {
+    const noEntries = getPortfolioWizardProgress({ ...completeInput, sections: [], assets: [] });
+    expect(noEntries.find((s) => s.key === "sections")?.summary).toBe("Optional — no sections added.");
+    expect(noEntries.find((s) => s.key === "assets")?.summary).toBe(
+      "Optional — no gallery assets added.",
+    );
+  });
+
+  it("blocks saving when an added section is incomplete", () => {
+    const progress = getPortfolioWizardProgress({
+      ...completeInput,
+      sections: [section({ titleEn: "" })],
+    });
+    expect(progress.find((s) => s.key === "sections")?.complete).toBe(false);
+    expect(getFirstIncompleteWizardStep(progress)).toBe("sections");
   });
 
   it("summarizes section/asset readiness counts", () => {