Update CSS and E2E test for toolbar scene name

src/app/app.css

@@ -81,23 +81,13 @@ button:disabled {
   border-radius: 18px;
   box-shadow: var(--shadow-panel);
   backdrop-filter: blur(16px);
+  min-width: 0;
 }
 
-.toolbar__brand {
-  display: flex;
-  flex-direction: column;
-}
-
-.toolbar__title {
-  font-size: 1rem;
-  font-weight: 700;
-  letter-spacing: 0.12em;
-  text-transform: uppercase;
-}
-
-.toolbar__subtitle {
-  color: var(--color-muted);
-  font-size: 0.78rem;
+.toolbar__scene-name {
+  flex: 1 1 320px;
+  min-width: 220px;
+  max-width: 520px;
 }
 
 .toolbar__actions {
@@ -106,6 +96,7 @@ button:disabled {
   justify-content: flex-end;
   gap: 8px;
   flex-wrap: wrap;
+  min-width: 0;
 }
 
 .toolbar__group {
@@ -143,6 +134,13 @@ button:disabled {
   box-shadow: inset 0 0 0 1px rgba(255, 241, 213, 0.28);
 }
 
+.toolbar__scene-name-input {
+  height: 44px;
+  padding: 0 14px;
+  font-size: 1rem;
+  font-weight: 700;
+}
+
 .workspace {
   display: grid;
   grid-template-columns: minmax(240px, 280px) minmax(0, 1fr) minmax(280px, 320px);

tests/e2e/app-smoke.e2e.ts

@@ -16,7 +16,7 @@ test("app boots and shows the viewport shell", async ({ page }) => {
 
   await page.goto("/");
 
-  await expect(page.getByText("WebEditor3D")).toBeVisible();
+  await expect(page.getByTestId("toolbar-scene-name")).toHaveValue("Untitled Scene");
   await expect(page.getByTestId("viewport-shell")).toBeVisible();
   await expect(page.getByTestId("enter-run-mode")).toBeVisible();