The r6 soak hard-fails without 'move-truth OUT' lines, yet the only
automated guard was a text assertion that the SCRIPT sets the env var —
it stayed green while #435 part 2 deleted the emitter, and the breakage
would have surfaced as a misleading connected-gate failure. The new
contract test asserts all four links of the chain in one place: the
script greps the pattern, MovementTruthDiagnosticController still emits
it, RuntimeOptions still parses the flag, and GameWindow still wires it
through. Deleting any link fails here, at build time, with the reason.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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