Validate then freeze the strategy — call when ready to backtest, after all entries/exits/gates are attached and sizing/risk are configured.

Validates completeness first. Bidirectional strategies may contain one long and one short entry group and must use flat-only single-position market execution. If validation has errors it raises VALIDATION_ERROR with the specific problems and does not create a revision — fix the issues and call again. Warnings (e.g. no exit attached) do not block compilation and are returned in the result.

The returned entry_behavior makes reversal semantics explicit: same-bar reversal is disabled. An opposite signal on an exit bar cannot enter; its complete group must fire again on a later bar while flat. Directional exits expose applies_to; an exit applying to both sides reports [long, short].

Returns a blueprint and revision_id; the next call is run_backtest(strategy_id=...), which uses the latest revision. Safe to call repeatedly; each call snapshots the current state into a new revision.