[Bug] MCP permission approval prompts unreachable in tmux teammate mode

Bug Description
Team agent MCP permission approvals broken in tmux teammate mode — prompts unreachable

Environment:

• Claude Code launched with claude --teammate-mode tmux
• CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1
• macOS, tmux-backed team agents
• MCP tools via claude.ai connectors (tested: DataDog, Slack)

Expected behavior:
When a team agent needs permission to use a tool, the approval prompt is surfaced to the user in the main team-lead conversation window — matching the behavior that already works correctly for non-tmux foreground agents.

Actual behavior:

1. Team agent tries to use a tool requiring permission
2. A permission prompt appears in the agent's tmux pane — but the pane does not accept interactive input, so the user cannot approve it there
3. The agent sits waiting indefinitely
4. The team-lead (main conversation window) never surfaces an approval prompt to the user — no "Allow this tool?" appears there either
5. The only resolution is manually killing the agents

Note: This works correctly outside of tmux teammate mode. Foreground agents running in the main conversation surface permission prompts as expected. This issue is specific to --teammate-mode tmux.

Steps to reproduce:

1. Launch Claude Code with claude --teammate-mode tmux
2. Enable CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1
3. Create a team with TeamCreate
4. Spawn a team agent with a task that requires an MCP tool not in allowedTools
5. Observe: agent's tmux pane shows a permission prompt but is non-interactive; main conversation window never shows an approval request; agent is stuck indefinitely

Workaround:
Pre-approve the required tools in ~/.claude/settings.json under permissions.allow (e.g. "mcp__claude_ai_DataDog__*").

Additional context:

• The team-lead has no tmux pane (tmuxPaneId: "" in team config), so there is no real-time interactive channel for agents to escalate permission requests to
• Permission escalation via agent → team-lead messaging exists in the protocol but fails in practice because the team-lead only processes messages on the next user-triggered conversation turn, leaving the user with no actionable prompt

Environment Info

• Platform: darwin
• Terminal: tmux
• Version: 2.1.101
• Feedback ID: 8084033c-0b24-476c-86e8-0fca997adbba

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/jason.mctaggart/.local/share/claude/versions/2.1.101 (expected in multi-process scenarios)\n    at Oc_ (/$bunfs/root/src/entrypoints/cli.js:2836:2153)\n    at Ve6 (/$bunfs/root/src/entrypoints/cli.js:2836:1233)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-10T19:26:04.174Z"}]