cinny config: status banner from the Kuma page (cinny #124)

Adds `statusPages` for matrix.lotusguild.org → the Kuma status page
https://isitup.lotusguild.org/status/matrix (groups Homeserver, Voice
calls, Login). The banner code (cinny #255) and the CSP (#16) are already
live; production's config.json comes from this file, so without this entry
the client never asks Kuma. The LXC 106 deploy merges it into the live file
and keeps server-only values.

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

cinny/config.json

@@ -17,5 +17,16 @@
     "basename": "/"
   },
   "gifApiKey": "",
-  "elementCallUrl": "https://call.chat.lotusguild.org/public/element-call/index.html"
+  "elementCallUrl": "https://call.chat.lotusguild.org/public/element-call/index.html",
+  "statusPages": {
+    "matrix.lotusguild.org": {
+      "url": "https://isitup.lotusguild.org",
+      "slug": "matrix",
+      "groups": {
+        "homeserver": "Homeserver",
+        "calls": "Voice calls",
+        "login": "Login"
+      }
+    }
+  }
 }