Ark: real-time receives over the SubscribeMailbox gRPC stream

grpcStream() parses gRPC-web frames incrementally off fetch's body
stream; the manager keeps a long-lived SubscribeMailbox subscription
(auto-reconnect, 3s backoff) whose messages flow through the same
duplicate-safe processing as the poll. Receives now land the moment the
sender delivers (~sub-second) instead of on the next poll; the poll
stays as fallback and to drive in-flight boards/refreshes.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01QFAcD4V284DvYZZHP7Rxxy

1 files changed, 4 insertions, 1 deletions

diff --git a/src/app.js b/src/app.js
index 61b453b..efb0bc4 100644
--- a/src/app.js
+++ b/src/app.js
@@ -42,6 +42,7 @@ function stopArk() {
   arkInitGen++;
   if (arkTimer) clearInterval(arkTimer);
   arkTimer = null;
+  if (ark) ark.stopMailboxStream();
   ark = null;
   arkConnectPromise = null;
 }
@@ -89,7 +90,9 @@ function connectArk() {
     ark = mgr;
     const tick = () => mgr.sync().catch(() => {});
     tick();
-    // Regtest rounds are seconds apart; on mainnet a slower poll is plenty.
+    // Receives arrive in real time over the mailbox stream; the poll is the
+    // fallback and what drives in-flight boards/refreshes forward.
+    mgr.startMailboxStream();
     arkTimer = setInterval(() => { if (ark === mgr) tick(); }, getNetwork() === 'regtest' ? 5000 : 30000);
     render();
     return mgr;