Fix asx-trading integration test failures

Fix the 8 integration test failures and 1 error in factor_screen.py. Fixture mismatch found during Jun 25 audit. The signal_engine.py implements SMA crossover, not the dividend-factor V2 engine from the design doc.\n\nAction items:\n1. Run the test suite to confirm current state\n2. Examine factor_screen.py fixture definitions vs actual usage\n3. Fix fixtures to match signal_engine.py API (SMA crossover)\n4. Wire fee_gate and risk modules into runner.py\n5. All tests pass green\n

Note (2026-06-28T14:57:16Z)

Picked up by ralph at 2026-06-28T15:30+10. Plan: run test suite, examine fixtures vs actual signal_engine API, fix mismatches.