app/page.jsx

@@ -1,7 +1,7 @@
 "use client";
 
 import React from "react";
-import { loadInvestigation } from "@/lib/storage/investigation-storage";
+import { loadInvestigation, clearInvestigation } from "@/lib/storage/investigation-storage";
 import Link from "next/link";
 
 const INVESTIGATION_ID = "case-1";
@@ -50,15 +50,17 @@ function Portfolio() {
                 href={`/investigations/${INVESTIGATION_ID}`}
                 className="rounded-lg border border-teal-600 bg-white px-4 py-2 font-medium text-teal-700 hover:bg-teal-50 transition"
               >
-                Open investigation
+                Continue investigation
               </Link>
 
-              <Link
-                href={`/investigations/${INVESTIGATION_ID}`}
-                className="rounded-lg border border-teal-600 bg-white px-4 py-2 font-medium text-teal-700 hover:bg-teal-50 transition"
+              <button
+                onClick={() => {
+                  try { clearInvestigation(); } catch (_) { /* storage must not crash caller */ }
+                }}
+                className="rounded-lg border border-red-400 bg-white px-4 py-2 font-medium text-red-700 hover:bg-red-50 transition"
               >
-                Create new investigation
-              </Link>
+                Restart investigation
+              </button>
             </div>
           </div>
         </section>

docs/current-handoff.md

@@ -499,3 +499,32 @@ Investigation Report
 **Key insight for future work:** Portfolio's initial pre-hydration empty state (`No investigations yet.`) ≠ absence of persisted investigation. Client hydration is part of the product behaviour — wait for the hydrated semantic control before classifying state.
 
 **Next restart point:** The empty-Done `no_episodic_content` 400. Implement and verify that a Done action taken when no episodic evidence exists produces the same user-facing state (CU refresh with appropriate messaging) without a 400 error.
+
+### v0.56 — Portfolio existing-case actions semantics (verified)
+
+**Objective:** Make one bounded portfolio UI correction — clarify that actions on an existing investigation card are distinct from creation of a new investigation.
+
+**Changes applied:**
+- `app/page.jsx`: Renamed card-level "Open investigation" → "Continue investigation"; replaced card-level "Create new investigation" link with "Restart investigation" button wired to `clearInvestigation()`; preserved portfolio-level "+ Create new investigation" below the card.
+- `tests/ui/investigation-overview-ui.test.jsx`: Updated assertions for renamed links, added tests for "Continue investigation" presence, "Open investigation" absence, "Restart investigation" presence, and card-level duplicate creation control absence.
+
+**Resulting Portfolio semantics:**
+
+```
+Existing-investigation card (when one persists):
+  View report           → /investigations/:id/report     (link)
+  Continue investigation → /investigations/:id            (link)
+  Restart investigation  → clearInvestigation()          (button)
+
+Portfolio-level (always visible below card):
+  + Create new investigation → /investigations/:id       (link)
+```
+
+**Restart investigation wiring:** Invokes `clearInvestigation()` from `lib/storage/providers/local-storage.js` which removes the canonical localStorage key. Note: this is a raw storage clear — it does not perform the in-memory state resets (`setStatus`, `setResult`, etc.) that scenario-form.jsx also performs as part of its complete restart flow (lines ~913/941). The button clears persisted data and navigates to the investigation page which detects empty state; the user sees "Your previous investigation state is still saved" with Restart/Start new options. A full confirmation dialog and/or unified restart seam is a future increment.
+
+**Verification:**
+- Targeted Vitest (`tests/ui/investigation-overview-ui.test.jsx`): 17/17 PASS
+- Build: `npm run build` — compiles successfully, zero errors
+- Playwright live verification: persisted card hydrated with View report + Continue investigation + Restart investigation; no "Open investigation"; no duplicate "Create new investigation" in card; exactly one portfolio-level "+ Create new investigation"; navigation to Investigation and Report pages verified; persisted state retained across navigate-back.
+
+**Restart ownership:** Raw storage clear available via `lib/storage/providers/local-storage.js::clearInvestigation()`. Complete restart seam (storage + in-memory state resets) is owned by `scenario-form.jsx` lines ~913-941. No confirmation dialog currently exists for either seam — adding one is a future increment boundary.

tests/ui/investigation-overview-ui.test.jsx

@@ -1,14 +1,22 @@
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import React from "react";
-import { render, screen } from "@testing-library/react";
+import { render, screen, fireEvent } from "@testing-library/react";
 import "@testing-library/jest-dom";
 
 vi.mock("next/navigation", () => ({
   useRouter: () => ({ push: () => {} }),
 }));
 
+vi.mock("@/lib/storage/investigation-storage", async (importOriginal) => {
+  const actual = await importOriginal();
+  return {
+    ...actual,
+    clearInvestigation: vi.fn(),
+  };
+});
+
 // ---------------------------------------------------------------------------
-// Route-level assertions for v0.55 architecture
+// Route-level assertions for v0.55 architecture + v0.56 action semantics
 // Portfolio = /index ; Investigation Report = dedicated page
 // ---------------------------------------------------------------------------
 
@@ -48,16 +56,34 @@ describe("Portfolio page (v0.55 route architecture)", () => {
     localStorage.clear();
     render(React.createElement(Portfolio));
     expect(await screen.findByText(/Create new investigation/i)).toBeInTheDocument();
+    // Open/Continue investigation buttons absent when no investigation exists
     expect(screen.queryByText(/Open investigation/i)).not.toBeInTheDocument();
+    expect(screen.queryByText(/Continue investigation/i)).not.toBeInTheDocument();
   });
 
-  it("shows Open investigation card when one persisted investigation exists", async () => {
+  it("does not show Restart investigation when no investigation exists", async () => {
+    localStorage.clear();
+    render(React.createElement(Portfolio));
+    expect(screen.queryByText(/Restart investigation/i)).not.toBeInTheDocument();
+  });
+
+  it("shows Continue investigation card when one persisted investigation exists", async () => {
     localStorage.setItem(
       "confidence-engine-investigation",
       JSON.stringify(makeSnapshot()),
     );
     render(React.createElement(Portfolio));
-    expect(await screen.findByText(/Open investigation/i)).toBeInTheDocument();
+    expect(await screen.findByText(/Continue investigation/i)).toBeInTheDocument();
+    localStorage.removeItem("confidence-engine-investigation");
+  });
+
+  it("does not show Open investigation text when one persisted investigation exists", async () => {
+    localStorage.setItem(
+      "confidence-engine-investigation",
+      JSON.stringify(makeSnapshot()),
+    );
+    render(React.createElement(Portfolio));
+    expect(screen.queryByText(/Open investigation/i)).not.toBeInTheDocument();
     localStorage.removeItem("confidence-engine-investigation");
   });
 
@@ -87,6 +113,31 @@ describe("Portfolio page (v0.55 route architecture)", () => {
     expect(screen.queryByText(/View report/i)).not.toBeInTheDocument();
     localStorage.removeItem("confidence-engine-investigation");
   });
+
+  it("shows Restart investigation button when one persisted investigation exists", async () => {
+    localStorage.setItem(
+      "confidence-engine-investigation",
+      JSON.stringify(makeSnapshot()),
+    );
+    render(React.createElement(Portfolio));
+    expect(await screen.findByText(/Restart investigation/i)).toBeInTheDocument();
+    localStorage.removeItem("confidence-engine-investigation");
+  });
+
+  it("card does not contain Create new investigation when one persisted investigation exists", async () => {
+    localStorage.setItem(
+      "confidence-engine-investigation",
+      JSON.stringify(makeSnapshot()),
+    );
+    render(React.createElement(Portfolio));
+    // Portfolio-level "+ Create new investigation" is still present (below card)
+    expect(await screen.findByText(/Create new investigation/i)).toBeInTheDocument();
+    // But the investigations section card does NOT contain it (no duplicate)
+    const card = document.querySelector("section.mb-10");
+    const btns = Array.from(card.querySelectorAll('a,button'));
+    expect(btns.some(el => /Create new investigation/i.test(el.textContent))).toBe(false);
+    localStorage.removeItem("confidence-engine-investigation");
+  });
 });
 
 describe("Investigation Report page (v0.55 route architecture)", () => {