test_agents had no harness.require() and FrameTestCase started ui/server.py
unconditionally, so plain discovery over tests/e2e started a server on this
computer's real app data, ~/.ssh and cache. FRAME_E2E=1 alone outside the
container did the same with the real cache.
require() now also needs FRAME_E2E_CONTAINER=1 (set in compose.yaml) and the
container runtime's marker file, and says why it refuses; FrameTestCase and
Server.start call it before starting anything; test_agents calls it at
module level. test_sandbox checks discovery over tests/e2e, with and
without FRAME_E2E=1, skips everything and starts no server.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
