[BUG] Terminal panel: Couldn't send the command's output to Claude - shell silently reconnects mid-command

Description
The built-in Terminal panel in Claude Desktop intermittently fails to relay command output to the chat session, showing the toast: "Couldn't send the command's output to Claude. Check the terminal tab." Inside the terminal panel itself, this coincides with the line [shell reconnected — replaying buffered output], indicating the terminal's connection to the session dropped and re-established mid-command.

Steps to reproduce

1. Open the Terminal panel in Claude Desktop (macOS)
2. Run a multi-second command, e.g.:

for i in {1..10}; do echo "line $i"; sleep 1; done

1. Observe the toast error appearing, sometimes with garbled/interleaved input text in the terminal (characters from the typed command appear reordered)
2. The command itself completes successfully (checked via the read_terminal MCP tool, which independently confirms full correct output) — only the live relay to chat fails

What I've ruled out

• Not caused by a slow shell: zsh -i -c exit startup measured at ~15ms
• Not caused by .zshrc/.zprofile content: no precmd/preexec hooks, no gh CLI shell integration, no syntax errors (zsh -n clean)
• Not caused by GitHub CLI (gh) installation: no shell rc hooks added by gh
• Not caused by a connected GitHub connector: issue persists after fully disconnecting it and restarting the app
• Not caused by hitting usage limits: at time of reproduction, 5-hour usage was 35%, weekly was 76% — nowhere near the cap
• Full app restart (Cmd+Q, relaunch) does not resolve it
• Recurs across multiple separate terminal tabs/sessions, not tied to one tab

Environment

• Claude Desktop, macOS (Darwin 27.0.0, Apple Silicon)
• Default shell: zsh
• Plan: Pro

Impact
Recurs on effectively every terminal command run from the app's Terminal panel, making it unreliable as a live-feedback channel — have to fall back to manually asking Claude to re-read terminal output via the read_terminal tool as a workaround.