feat(call): stop injecting CSS and key listeners into the call frame (#43)

Pins @lotusguild/element-call-embedded 0.25.0-lotus.19.

- Styles: the fork now hides its own footer (`lotusHostControls=1`) and
  sets its root color-scheme from the theme, so the host no longer
  injects `#lotus-ec-styles` or sets inline styles on EC's DOM. The two
  other injected rules matched nothing in EC 0.25 (dead). The
  transparent background was already the fork's (`lotusTransparent`).
- Hotkeys: PTT / deafen keys pressed with focus inside the call frame now
  arrive as `io.lotus.hotkey` (the host sends the codes via
  `io.lotus.set_hotkeys`), instead of listeners on the frame's window.
  The window binding stays only for a fork that doesn't report `hotkeys`.
- Fixes (with lotus.19): pressing the deafen key M with focus in the call
  also hit EC's own "M = toggle mic" shortcut, so the first press turned
  the mic ON instead of deafening — even in push-to-talk mode.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/plugins/call/forkHotkeyReport.test.ts

@@ -0,0 +1,40 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { parseForkHotkeyReport } from './CallControl';
+
+test('parseForkHotkeyReport: key reports keep only known boolean flags', () => {
+  assert.deepEqual(
+    parseForkHotkeyReport({
+      type: 'keydown',
+      code: 'Space',
+      repeat: false,
+      ctrlKey: false,
+      altKey: 'yes',
+      metaKey: false,
+      shiftKey: true,
+      editable: false,
+      interactive: true,
+      extra: 1,
+    }),
+    {
+      type: 'keydown',
+      code: 'Space',
+      repeat: false,
+      ctrlKey: false,
+      altKey: false,
+      metaKey: false,
+      shiftKey: true,
+      editable: false,
+      interactive: true,
+    },
+  );
+  assert.equal(parseForkHotkeyReport({ type: 'keyup', code: 'KeyM' })?.type, 'keyup');
+});
+
+test('parseForkHotkeyReport: focus reports and junk', () => {
+  assert.deepEqual(parseForkHotkeyReport({ type: 'focus' }), { type: 'focus' });
+  assert.equal(parseForkHotkeyReport({ type: 'keydown' }), null);
+  assert.equal(parseForkHotkeyReport({ type: 'click', code: 'Space' }), null);
+  assert.equal(parseForkHotkeyReport(null), null);
+  assert.equal(parseForkHotkeyReport('keydown'), null);
+});