v2.0.9 — sync toast split, relay group chat UI, find/replace flaky fix

- sync: the post-sync toast lumped relay pulls into the CalDAV stats
  and always labelled the banner "CalDAV". Split into two separate
  toasts (CalDAV cloud-arrow + Relay broadcast icon), each only shown
  when its numbers are non-zero. Banners now stack vertically so both
  can appear together on a sync that pulled on both sides.
- relay UI: the session chat view was 1:1-only. Group rooms (which
  the client API already supports) now surface as first-class threads
  in the sidebar — sorted chronologically with 1:1 peers, tagged
  "ROOM", with a users-three icon. Sending posts to `room_uid`
  instead of `recipient`; history shows the sender name above each
  incoming message so it's clear who's talking in the room.
  Relay backend: `/api/chat/threads` returns rooms alongside 1:1
  threads; `/api/chat/history` accepts `?room_uid=`; `/api/chat/send`
  accepts `room_uid` in the body.
- tests: bump "replace all updates card bodies" poll budget from 4s
  to 10s and poll both updated cards. Flaky on cold runs because a
  fresh PHP worker + SQLite WAL warm-up plus two sequential PATCH
  calls can just barely exceed 4 seconds.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

config.php

@@ -1,7 +1,7 @@
 <?php
 
 define('APP_NAME', 'hyprcrd');
-define('APP_VERSION', '2.0.8');
+define('APP_VERSION', '2.0.9');
 
 // APP_DEBUG: gates verbose error responses (curl traces, upstream bodies).
 // Off by default; enable via env for local troubleshooting only.