feat(lotus): expected-device check before joining (cinny #121)

EC remembers the picked mic / output by id and silently falls back to the
first device when it is missing, so a user who always joins with a headset
lands on the laptop mic. With lotusDeviceCheck=1:
- the last-picked device's NAME is remembered next to its id
  (lotus-audio-{input,output}-name), since ids can change on re-plug;
- before the automatic join, a usual device that is gone is reported to the
  host (io.lotus.device_missing) and EC waits for io.lotus.device_decision
  { join }; one that came back under a new id is just re-selected;
- in a call, losing it is reported (io.lotus.device_lost) for a toast.
Fails open (no names / no host / nothing remembered). Without the flag the
join stays synchronous, as upstream. The gate runs once per call: CallView's
effect re-runs while its inputs settle and must not restart it.

Embedded version 0.28.0-lotus.2.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

embedded/web/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lotusguild/element-call-embedded",
-  "version": "0.28.0-lotus.1",
+  "version": "0.28.0-lotus.2",
   "files": [
     "README.md",
     "LICENSE-AGPL-3.0",