[Bug] Agent teammate process crashes on startup with TypeError "Line number must start from 1"

Bug Description
Agent teammate process crashes on startup with TypeError "Line number must start from 1" in
cli.js (createInstance → Yo8). Repro: TeamCreate + Agent spawn in tmux with teammateMode "tmux".
Crashes consistently within first 30s of teammate's first turn before any user-facing output.
Started 2026-04-26.

Environment Info

• Platform: linux
• Terminal: tmux
• Version: 2.1.119
• Feedback ID: 46300f7e-ba02-48dd-8594-c27ebeb654e3

Errors

[{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server github invalid: Missing environment variables: GITHUB_PERSONAL_ACCESS_TOKEN\n    at f2H (/$bunfs/root/src/entrypoints/cli.js:2738:30496)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-28T05:47:10.858Z"},{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server github invalid: Missing environment variables: GITHUB_PERSONAL_ACCESS_TOKEN\n    at f2H (/$bunfs/root/src/entrypoints/cli.js:2738:30496)\n    at async G (/$bunfs/root/src/entrypoints/cli.js:6296:11019)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-28T05:47:15.946Z"},{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server github invalid: Missing environment variables: GITHUB_PERSONAL_ACCESS_TOKEN\n    at f2H (/$bunfs/root/src/entrypoints/cli.js:2738:30496)\n    at async v (/$bunfs/root/src/entrypoints/cli.js:6296:11825)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-28T05:47:15.947Z"}]

<img width="2435" height="1346" alt="Image" src="https://github.com/user-attachments/assets/253b144d-db48-4e63-a67f-718bf15fdc9e" />