feat: show research chat history as full-width tabs

e2e/integrations/research.test.ts

@@ -347,6 +347,17 @@ test("keeps browser conversation selection independent and restores it on reload
     const secondWorkspace = new WorkspacePage(secondPage);
     await researchPage.goTo(`?run=${first}`, { waitUntil: "domcontentloaded" });
     await workspacePage.showResearch();
+    const history = page.getByRole("navigation", { name: "Chat history" });
+    const firstTab = history.getByRole("button", { name: "Browser one conversation" });
+    const secondTab = history.getByRole("button", { name: "Browser two conversation" });
+    await expect(firstTab).toHaveAttribute("aria-current", "page");
+    await workspacePage.showDeckManagement();
+    await secondTab.click();
+    await expect(page).toHaveURL(new RegExp(`run=${second}`));
+    await expect(secondTab).toHaveAttribute("aria-current", "page");
+    await expect(researchPage.conversation).toContainText("Browser two conversation");
+    await page.goBack();
+    await expect(firstTab).toHaveAttribute("aria-current", "page");
     await secondResearch.goTo(`?run=${second}`, {
       waitUntil: "domcontentloaded",
     });

e2e/integrations/workspace.test.ts

@@ -13,6 +13,20 @@ test("keeps the sidebar, composer and deck reachable at compact widths", async (
     await workspacePage.showResearch();
     const chat = researchPage.panel;
     await expect(chat).toBeVisible();
+    const history = page.getByRole("navigation", { name: "Chat history" });
+    await expect(history).toBeVisible();
+    const historyBounds = await history.boundingBox();
+    const chatBounds = await chat.boundingBox();
+    if (!historyBounds || !chatBounds) throw new Error("Chat and history must have visible bounds");
+    expect(historyBounds.x).toBe(0);
+    const availableWidth =
+      width < 768
+        ? await page
+            .getByRole("dialog", { name: "Workspace" })
+            .evaluate((element) => element.clientWidth)
+        : width;
+    expect(historyBounds.width).toBe(availableWidth);
+    expect(historyBounds.y + historyBounds.height).toBeLessThanOrEqual(chatBounds.y);
     const composer = researchPage.composer;
     await expect(composer).toBeVisible();
     const bounds = await composer.boundingBox();