fix(stream): stop logging a disconnect for every completed Responses call

Responses-API clients (codex, droid) close the socket on
response.completed because the protocol has no [DONE] sentinel, so
every successful request printed "⚡ DISCONNECT: ResponseAborted"
after its own "📊 done" line. Keep the dbg("CTRL", …) trace and drop
the console line; ABORTED and ERROR still print.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

open-sse/utils/streamHandler.js

@@ -41,7 +41,8 @@ export function createStreamController({ onDisconnect, onError, log, provider, m
       if (disconnected) return;
       disconnected = true;
 
-      logStream("⚡", `DISCONNECT: ${reason}`);
+      // Debug-only: Responses API has no [DONE] sentinel, so codex/droid close the
+      // socket on every completed request. "📊 done" is the authoritative outcome line.
       dbg("CTRL", `${provider}/${model} | disconnect=${reason} | dur=${Date.now() - startTime}ms`);
 
       // Delay abort to allow cleanup