Investigate large message/file payloads causing apparent disconnects

[chknlittle]

Problem

When a file or message payload reaches some maximum size, the macOS UI appears to falter instead of failing gracefully. From the user perspective it can look like the session disconnected, even though the underlying problem may be payload size or related transport/server behavior.

Observed behavior

• UI stops behaving normally once a string/file payload crosses a certain size threshold
• failure mode looks like a disconnect rather than a clear validation or delivery error
• possible interaction between switch-mac-os client behavior and server-side handling of oversized payloads

Questions to investigate

• What is the effective maximum payload size for message bodies / uploaded file metadata / rendered text?
• Does the client hit a rendering or state-management limit before the server rejects the payload?
• Does the server close the stream, drop the stanza, time out, or otherwise behave in a way that the client currently surfaces as a disconnect?
• Can the client detect this case and show a clear error instead of looking offline or disconnected?

Expected behavior

If a payload exceeds supported limits, the app should fail predictably with a clear user-facing error and stay connected if possible.

Possible directions

• reproduce with progressively larger payloads and log client/server behavior
• document hard limits if they exist
• add preflight validation or chunking where appropriate
• improve error handling so oversized payloads do not resemble connection loss