fix(presence): closing a tab no longer erases your custom status (#339)

The pagehide keepalive write sent { presence: 'offline' } with no
status_msg, which Synapse treats as clearing it, so closing or reloading
any Lotus tab wiped the user's status for everyone (intermittently, as
the 10 s presence rate limit sometimes 429'd the write). It now sends the
current status along with the offline state.

Verified against the local Synapse: with a status set from another
device, two reloads and a tab close keep it (server shows
offline/"Gone fishing" after the close; before, the first reload wiped it).

Fixes #339

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

src/app/hooks/usePresenceUpdater.ts

@@ -167,13 +167,17 @@ export function usePresenceUpdater() {
       // it isn't usable here. fetch(..., { keepalive: true }) lets the request outlive the
       // page and is the correct mechanism for an authed endpoint. (keepalive bodies are
       // capped at 64KB, which this tiny payload is well under.)
+      // [Gitea #339] Synapse treats a missing status_msg as "clear it", so a bare
+      // { presence: 'offline' } wiped the user's custom status for everyone whenever
+      // any tab closed or reloaded. Send the current status along with it.
+      const status = readStatus();
       fetch(`${baseUrl}/_matrix/client/v3/presence/${encodeURIComponent(userId)}/status`, {
         method: 'PUT',
         headers: {
           Authorization: `Bearer ${token}`,
           'Content-Type': 'application/json',
         },
-        body: JSON.stringify({ presence: 'offline' }),
+        body: JSON.stringify({ presence: 'offline', ...(status ? { status_msg: status } : {}) }),
         keepalive: true,
       }).catch((err) => warnPresenceFailure('offline (pagehide)', err));
     };