98be64ebdf
Milestone spec: ship the GER40 session-breakout as a Composite blueprint so the same strategy runs across backtest / sweep / walk_forward / compare without re-authoring (the #94 fieldtest friction). Records the design decision that the bar period is a structural axis (a construction arg binding both Resample and Session, so a sweep cannot desync them — #96) and that the canonical shippable strategy form is a Composite (FlatGraph is its compiled substrate). Authoring- side; no engine-core change (the existing bind() + GraphBuilder + param_space() layer already suffices). refs #94, #96, #97