fix(app): keep theme selection consistent (#3214)

Theme registration, the appearance picker, persistence, and shortcut cycling drifted as new choices were added. Make one ordered catalog own those paths so Auto and Pure Black participate consistently, while lifting the Pure Black selected-workspace surface above its sidebar.

packages/app/e2e/browser/appearance-theme-picker.spec.ts

@@ -1,4 +1,7 @@
 import { expect, test } from "../support/fixtures";
+import { gotoAppShell } from "../support/helpers/app";
+import { seedWorkspace } from "../support/helpers/seed-client";
+import { getServerId } from "../support/helpers/server-id";
 import { openSettingsSection } from "../support/helpers/settings";
 
 test("shows Pure black in the appearance picker", async ({ page }, testInfo) => {
@@ -15,6 +18,33 @@ test("shows Pure black in the appearance picker", async ({ page }, testInfo) =>
   });
 });
 
+test("keeps the selected workspace visible in Pure black", async ({ page }, testInfo) => {
+  const workspace = await seedWorkspace({
+    repoPrefix: "pure-black-selected-workspace-",
+    title: "Selected workspace",
+  });
+
+  try {
+    await page.addInitScript(() => {
+      localStorage.setItem("@paseo:app-settings", JSON.stringify({ theme: "pureBlack" }));
+    });
+    await gotoAppShell(page);
+
+    const row = page.getByTestId(`sidebar-workspace-row-${getServerId()}:${workspace.workspaceId}`);
+    await expect(row).toBeVisible({ timeout: 30_000 });
+    await row.click();
+
+    await expect(row).toHaveAttribute("aria-selected", "true");
+    await expect(row).toHaveCSS("background-color", "rgb(22, 22, 22)");
+    await page.screenshot({
+      path: testInfo.outputPath("pure-black-selected-workspace.png"),
+      fullPage: true,
+    });
+  } finally {
+    await workspace.cleanup();
+  }
+});
+
 test("applies the interface font size to settings text", async ({ page }) => {
   await page.addInitScript(() => {
     localStorage.setItem("@paseo:app-settings", JSON.stringify({ uiFontSize: 24 }));