fix(lotus): transparent-theme contrast guard; phone-only rail shrink; live URL params

- lotusTransparent without lotusTheme warns and applies the theme anyway;
  name tags/header/footer get a subtle text-shadow + backdrop blur under
  body.lotus-transparent (#21).
- Landscape filmstrip shrink requires (pointer: coarse) so a short
  desktop/PiP window isn't reflowed as a phone (#32).
- lotusParam re-reads window.location on every call (#33).

Fixes #21
Fixes #32
Fixes #33

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/lotus/lotusWidget.test.ts

@@ -0,0 +1,85 @@
+/*
+Copyright 2026 Lotus Guild
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { afterEach, describe, expect, test, vi } from "vitest";
+
+vi.mock("../widget", () => ({ widget: null }));
+
+import { lotusFlag, lotusParam, lotusSendToHost } from "./lotusWidget";
+import { LotusWidgetActions } from "./lotusActions";
+
+/**
+ * Point `window.location` at a URL for the duration of one assertion. Uses a
+ * path relative to the current origin — `pushState` throws a `SecurityError`
+ * on a cross-origin URL, and jsdom's default test origin doesn't match a
+ * hard-coded `http://localhost/`.
+ */
+function setLocation(path: string): void {
+  window.history.pushState({}, "", path);
+}
+
+describe("lotusParam / lotusFlag", () => {
+  afterEach(() => {
+    setLocation("/");
+  });
+
+  test("reads a param from the query string", () => {
+    setLocation("/?lotusTheme=1");
+    expect(lotusParam("lotusTheme")).toBe("1");
+  });
+
+  test("reads a param from the hash fragment's query portion", () => {
+    setLocation("/#/room?lotusTransparent=1");
+    expect(lotusParam("lotusTransparent")).toBe("1");
+  });
+
+  test("the hash fragment wins over the query string for the same key", () => {
+    setLocation("/?lotusTheme=fromQuery#/room?lotusTheme=fromHash");
+    expect(lotusParam("lotusTheme")).toBe("fromHash");
+  });
+
+  test("falls back to the query string for keys absent from the hash", () => {
+    setLocation("/?onlyInQuery=1#/room?lotusTheme=1");
+    expect(lotusParam("onlyInQuery")).toBe("1");
+  });
+
+  test("returns null when the param is present nowhere", () => {
+    setLocation("/#/room");
+    expect(lotusParam("missing")).toBeNull();
+  });
+
+  test.each([
+    ["1", true],
+    ["true", true],
+    ["0", false],
+    ["false", false],
+    [null, false],
+  ])("lotusFlag treats %s as %s", (value, expected) => {
+    setLocation(value === null ? "/" : `/?f=${value}`);
+    expect(lotusFlag("f")).toBe(expected);
+  });
+
+  // [lotus #33] lotusParam must re-derive from window.location on every call
+  // rather than caching the first read, so a later navigation (e.g. lobby ->
+  // in-call) that rewrites the URL is picked up.
+  test("re-reads window.location on every call instead of caching the first result", () => {
+    setLocation("/?lotusTheme=1");
+    expect(lotusParam("lotusTheme")).toBe("1");
+
+    setLocation("/?lotusTheme=0");
+    expect(lotusParam("lotusTheme")).toBe("0");
+
+    setLocation("/");
+    expect(lotusParam("lotusTheme")).toBeNull();
+  });
+});
+
+describe("lotusSendToHost", () => {
+  test("returns false when no widget transport is available", () => {
+    expect(lotusSendToHost(LotusWidgetActions.CallState, {})).toBe(false);
+  });
+});