test(ui): migrate suite to the app-shell (state-driven navigation)

- Unit: repoint moved screen imports (lib/screens, lib/game), mock
  $lib/app-nav (appScreen/activeView) instead of $app/navigation, drop the
  removed gameId props, assert screen/view selection.
- e2e: add a dev-only window.__galaxyNav affordance; specs enter a game via
  enterGame(...) instead of a /games/:id URL; URL assertions become content
  assertions (the URL stays /game/); reload uses waitUntil:"commit" (shallow
  routing) and mocks /rpc on game entry.
- Remove the obsolete report scroll-restore test (it relied on a SvelteKit
  route Snapshot that no longer exists); update the missing-membership test
  to the new lobby-redirect+toast behaviour. Fix a stale report.svelte
  docstring.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ui/frontend/tests/e2e/inspector-ship-group.spec.ts

@@ -136,7 +136,9 @@ test("synthetic-report loader navigates from lobby to map and renders", async ({
 	page,
 }) => {
 	await seedSession(page);
-	await page.goto("/lobby");
+	// Seeded session → the dispatcher renders the lobby; the synthetic
+	// loader lives there behind the dev-affordances flag.
+	await page.goto("/");
 	await expect(page.getByTestId("lobby-synthetic-section")).toBeVisible();
 
 	const file = page.getByTestId("lobby-synthetic-file");
@@ -146,9 +148,10 @@ test("synthetic-report loader navigates from lobby to map and renders", async ({
 		buffer: Buffer.from(JSON.stringify(SYNTHETIC_REPORT_FIXTURE)),
 	});
 
-	await page.waitForURL(/\/games\/synthetic-[^/]+\/map$/, {
-		timeout: 5_000,
-	});
+	// Loading the report enters the game in place (the address bar stays
+	// at the app base); the in-game map shell is the visible signal.
+	await expect(page.getByTestId("game-shell")).toBeVisible({ timeout: 5_000 });
+	await expect(page.getByTestId("active-view-map")).toBeVisible();
 
 	// The renderer canvas mounts inside the active-view host. Even if
 	// the WebGL/WebGPU backend is unavailable in CI, the layout still