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/pwa/pwa.spec.ts

@@ -3,12 +3,15 @@
 // registration, offline-from-cache load, and the version-keyed cache
 // (a new deploy's `version` makes a new cache and `activate` drops the
 // old one — verified here as "exactly one galaxy cache, version-keyed").
+// The single-URL app-shell boots at the app base (`/`); with no seeded
+// session the dispatcher renders the login screen, so the shell's
+// `#main-content` region is the boot signal here.
 
 import { expect, test } from "@playwright/test";
 
 test.describe("PWA", () => {
 	test("links a web manifest with installable icons", async ({ page }) => {
-		await page.goto("/login");
+		await page.goto("/");
 		const href = await page
 			.locator('head link[rel="manifest"]')
 			.getAttribute("href");
@@ -33,7 +36,7 @@ test.describe("PWA", () => {
 	});
 
 	test("registers a service worker that controls the page", async ({ page }) => {
-		await page.goto("/login");
+		await page.goto("/");
 		await page.waitForFunction(
 			() => navigator.serviceWorker.controller !== null,
 			null,
@@ -50,7 +53,7 @@ test.describe("PWA", () => {
 		page,
 		context,
 	}) => {
-		await page.goto("/login");
+		await page.goto("/");
 		await page.waitForFunction(
 			() => navigator.serviceWorker.controller !== null,
 			null,