perf interop test fails without venv-managed tooling and timeout hardening

[acul71]

Summary

make pr and perf interop workflows can fail when the environment does not consistently resolve tooling from the project virtualenv, and the perf harness has timeout behavior that can cause negotiation/startup flakiness.

Reproduction

1. Run perf interop tests or make pr in an environment where system Python is used by default.
2. Observe failures from missing tooling (ruff/typecheck hooks) and occasional perf startup/negotiation instability.

Expected

Perf interop test setup is robust and reproducible, with stable timeout wiring and deterministic dependency resolution.

Proposed fix

• Ensure perf interop image/setup uses pinned constraints and predictable install path.
• Harden perf timeout configuration and QUIC-related wiring used during startup/negotiation.