fix(guest): deny favorites + auth-status reads to guests; UI polish

Consolidated fix wave from the final whole-branch review of guest mode.

- FIX 1 (critical): gate /api/favorites mount with requireNotGuest — the
  router keys off req.user.id (shared __guest__ principal), so guests could
  read/write a shared favorites bucket. Added focused guest-deny tests.
- FIX 2: gate GET /api/auth/status and /api/auth/qrcode/status with
  requireNotGuest so config reads no longer leak to guests.
- FIX 3: requireAuthInline in createSessionRouter now rejects guest sessions
  with 401 once guest mode is disabled (mirrors createRequireAuth), so /me
  stops returning guest data after an admin disables the feature.
- FIX 4: Login guest button now sits BELOW the card (auth-page flex-direction
  column + guest-btn width 360px) instead of beside it.
- FIX 5: mobile mini-player transport buttons in App.vue are now per-button
  gated for guests (prev/play/next/mode/volume), mirroring Player.vue.
- FIX 6: refreshed stale "gated on player.control" seek comments in Player.vue
  and relabeled the now-stale quality-GET test.

npm test: 354/354 pass. npm run build: tsc + vue-tsc + vite all green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/web/api/permissions-enforcement.test.ts

@@ -6,6 +6,8 @@ import { createPlayerRouter } from "./player.js";
 import { createBotRouter } from "./bot.js";
 import { createAuthRouter } from "./auth.js";
 import { createMusicRouter } from "./music.js";
+import { createFavoritesRouter } from "./favorites.js";
+import { requireNotGuest } from "../middleware/requireNotGuest.js";
 
 const logger = pino({ level: "silent" });
 
@@ -204,7 +206,7 @@ describe("permission enforcement on action routes", () => {
       expect(res.status).not.toBe(403);
     });
 
-    it("GET /api/music/quality not gated", async () => {
+    it("GET /api/music/quality readable by members, denied to guests", async () => {
       const app = makeApp(member([], "all"));
       const res = await request(app).get("/api/music/quality");
       expect(res.status).not.toBe(403);
@@ -215,6 +217,12 @@ describe("permission enforcement on action routes", () => {
       const res = await request(app).get("/api/bot");
       expect(res.status).not.toBe(403);
     });
+
+    it("GET /api/auth/status and /api/auth/qrcode/status are 403 for guests", async () => {
+      const app = makeApp(guest());
+      expect((await request(app).get("/api/auth/status")).status).toBe(403);
+      expect((await request(app).get("/api/auth/qrcode/status?key=k")).status).toBe(403);
+    });
   });
 
   describe("admin bypasses every gate", () => {
@@ -368,3 +376,48 @@ describe("guest enforcement on player routes", () => {
     expect((await request(m).post(`/api/player/${ALLOWED_BOT}/add-song`).send({ song: SONG })).status).not.toBe(403);
   });
 });
+
+// --------------------------------------------------------------------------
+// Favorites are member-only: the router keys everything off req.user.id and
+// all guests share the __guest__ principal, so a guest must never reach it.
+// server.ts gates the mount with requireNotGuest; we mirror that mount here
+// and assert a guest gets 403 (the requireNotGuest guard runs before any
+// handler, so the fake database is never touched).
+// --------------------------------------------------------------------------
+
+function makeFavoritesApp(user: any) {
+  const app = express();
+  app.use(express.json());
+  app.use((req, _res, next) => { (req as any).user = user; next(); });
+  const fakeDb = {
+    getFavorites: () => [],
+    addFavorite: () => {},
+    removeFavorite: () => {},
+    isFavorited: () => false,
+  } as any;
+  app.use("/api/favorites", requireNotGuest, createFavoritesRouter(fakeDb, logger));
+  return app;
+}
+
+describe("favorites are denied to guests", () => {
+  it("403 for a guest on GET /api/favorites", async () => {
+    const app = makeFavoritesApp(guest());
+    expect((await request(app).get("/api/favorites")).status).toBe(403);
+  });
+
+  it("403 for a guest on GET /api/favorites/check", async () => {
+    const app = makeFavoritesApp(guest());
+    expect((await request(app).get("/api/favorites/check?platform=netease&playlistId=x")).status).toBe(403);
+  });
+
+  it("403 for a guest on POST /api/favorites", async () => {
+    const app = makeFavoritesApp(guest());
+    const res = await request(app).post("/api/favorites").send({ platform: "netease", playlistId: "x", name: "n" });
+    expect(res.status).toBe(403);
+  });
+
+  it("NOT 403 for a member on GET /api/favorites", async () => {
+    const app = makeFavoritesApp(member([], "all"));
+    expect((await request(app).get("/api/favorites")).status).not.toBe(403);
+  });
+});