Add an "Open architectural threads" entry that ties together aura's differentiator
(C21): the composable-orchestration rebuild (sweep/MC/walk-forward as composable
tools, not hard-wired CLI verbs) + the project-as-crate authoring layer (aura new /
experiment-builder API / Aura.toml / cdylib loading, C16/C17). Records the
load-bearing open fork — "driven via the CLI" = running a Rust-authored experiment
(compatible with C16/C17/C22) vs wiring nodes through the CLI itself (a deliberate
amendment to C17/C22/C9) — to be resolved in the brainstorm before any cycle.
Keeps the meta-level in focus in the always-loaded design memory; #109 is its
tracker home. No design decided here (the fork is recorded, not resolved).
refs #109
Brummel
5a01179fd5