test(e2e): provide Docker daemon access to agent runs

[moncher-dev]

Problem

The Docker black-box command required by AGENT_TEST.md cannot run in the unattended Symphony worker environment because Docker Compose is installed but the daemon socket at /var/run/docker.sock is unreachable.

Observed twice while validating #904:

[e2e] Docker runtime unavailable: Docker Compose is installed, but the Docker daemon is not reachable.
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

The runner exits with its documented prerequisite status 69 before any scenario executes.

Expected

Agent runs that require Docker E2E should either receive a reachable isolated Docker daemon or have an orchestrator-supported execution path for the repository's black-box suite.

Reproduction

pnpm e2e:claude

Impact

Integration changes can complete unit, typecheck, lint, and build validation, but the mandatory Docker black-box gate requires a documented exception.

[moncher-dev]

Duplicate of #914 — same condition (Docker daemon unreachable at /var/run/docker.sock inside the Symphony worker environment, black-box gate exits on its prerequisite check). Consolidated there and assigned to @hojinzs as a host/execution-environment decision.