Feed is the canonical MODE=counters shape: each suite runs in a fresh session
with shared preloads and a single feed-test-pass/feed-test-fail pair. Lifted the
old script's inline epoch-2 counter + feed-test helper defs into
lib/feed/test-harness.sx (preloaded last) so the driver can load them before
each suite. conformance.conf + 3-line shim; historical scoreboard schema
preserved. No driver change needed.
Parity verified 189/189 (0 fail), every suite matching baseline.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>