feat(diagnostics): the debug recorder — start, the pill, steps, screenshots, stop (E16 S2)

- the start dialog is the consent: level (Részletes/Teljes), what is recorded,
  retention and the cap (now served as diagnostics.session_minutes)
- the pill docks under the toasts: elapsed time, Step (an optional label,
  its own Escape layer), Screenshot (tab capture where the browser has it),
  Stop; compact on a phone
- while recording, lib/log tags every event and every request path (req,
  beacon, uploadReq via one identityHeaders) names the session; applyDiagnostics
  raises the level for the session's run and never lowers a raised one, and
  lapses at whichever ends first
- Stop sends what is waiting before the server closes the session; the cap
  says so and opens the composer
- Settings → Diagnosztika and the command palette start/step/stop it
- the evidence leaves the log upload's own request lines out
- the step shortcut is deliberately palette-only: the keymap's D1 rule bars a
  new modifier chord, and a bare letter collides with the players'

frontend/src/components/AppCommandPalette.dom.test.tsx

@@ -10,7 +10,9 @@ import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
 import type { CommandGroup } from "./ui/CommandPalette";
 
-vi.mock("react-i18next", () => ({
+vi.mock("react-i18next", async (importOriginal) => ({
+  // The rest of the module too: the recorder's actions reach `i18n/index`, which needs it.
+  ...(await importOriginal<typeof import("react-i18next")>()),
   useTranslation: () => ({ t: (k: string) => k, i18n: { language: "en" } }),
 }));
 
@@ -140,4 +142,21 @@ describe("AppCommandPalette", () => {
     then?.();
     expect(requestSurprise).toHaveBeenCalledTimes(1);
   });
+
+  it("offers the debug recorder by its state, and not to the demo account", () => {
+    const recorder = () => ids("actions").filter((id) => id.startsWith("action:recorder:"));
+    mount();
+    expect(recorder()).toEqual(["action:recorder:start"]);
+
+    cleanup();
+    const until = new Date(Date.now() + 60_000).toISOString();
+    me = user({ debug_session: { id: "0123456789abcdef", until, ended_at: null } });
+    mount();
+    expect(recorder()).toEqual(["action:recorder:step", "action:recorder:stop"]);
+
+    cleanup();
+    me = user({ is_demo: true });
+    mount();
+    expect(recorder()).toEqual([]);
+  });
 });