fix(v1): bound null harness MCP connect at 60s

[eligotts]

Summary

• Wrap the null harness's connect_mcp in asyncio.wait_for(..., timeout=60) so a wedged streamable-HTTP handshake fails loudly instead of eating the whole rollout budget as a 0-turn harness_timeout.
• Incidental: this file was already out of format vs current ruff on main; touching it applies that format (no behavior change beyond the timeout).

Test plan

• Smoke a null-harness eval with MCP tools (happy path still connects)
• Optional: force a stuck connect and confirm it surfaces as a program error within ~60s

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Note

Low Risk
Isolated to the null eval harness startup path; improves failure visibility without touching auth, data, or shared production APIs.

Overview
MCP connect in the null harness is capped at 60 seconds so a stuck streamable-HTTP handshake fails with asyncio.TimeoutError instead of hanging until the rollout hits a 0-turn harness_timeout.

connect_mcp runs inside asyncio.timeout(60) when mcpServers is configured; the no-MCP path is unchanged. The implementation uses asyncio.timeout rather than wait_for so MCP/httpx cancel scopes registered on the shared AsyncExitStack are torn down in the same task.

The inline script metadata bumps requires-python to >=3.11, which is required for asyncio.timeout.

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Note

Bound null harness MCP connect with a 60s timeout

Wraps the connect_mcp call in program.py with asyncio.timeout(60) so MCP initialization fails with asyncio.TimeoutError after 60 seconds instead of waiting indefinitely. Also bumps the script's requires-python from >=3.10 to >=3.11, which is required for asyncio.timeout.

Changes since #1977 opened

• Replaced multi-line comment with shorter comment in main function [250a5c8]

^{Macroscope summarized cf5fa73.}

[macroscopeapp]

Approvability

Verdict: Approved

This is a straightforward defensive timeout addition (60s bound) to prevent indefinite hangs on MCP connection. The Python version bump from 3.10 to 3.11 is necessary for asyncio.timeout. Small, self-contained bug fix with clear intent.

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[eligotts]

Addressed the cancel-scope review: switched from asyncio.wait_for to async with asyncio.timeout(60) so MCP contexts entered onto the exit stack are cleaned up in the same task.