Add an opt-in plateau selection objective for walk-forward, recorded on the
same RunManifest.selection carrier #144 introduced. Default argmax is
byte-identical (C23); plateau is reached only via a new --select flag.
What landed:
- FamilySelection / SelectionMode reshape (report.rs): the selection RULE
(mode) and its ANNOTATION are orthogonal — deflation fields become Option
(present iff Argmax), plus PlateauMean/PlateauWorst variants and
neighbourhood_score/n_neighbours (present iff Plateau*). Legacy lines still
load: the deflation scalars deserialize from bare values via serde default
(C14/C18). compat.rs embeds FamilySelection by value — reshape flows through
untouched.
- GridSpace::axis_lens() + SweepBinder::sweep_with_lattice (engine): the grid
radixes in param_space()/odometer order. sweep() delegates to
sweep_with_lattice with the lattice dropped, so every existing .sweep()
caller is byte-unchanged.
- optimize_plateau + PlateauMode + closed_neighbourhood (aura-registry, C9):
each member scores as the mean/worst of its closed mixed-radix grid
neighbourhood's metric_value; the winner is the smoothed argmax by the
metric's direction (earliest-odometer tie, as optimize). Pure, no RNG (C1);
in-sample only (C2). A higher_is_better helper now sources the per-metric
direction once, shared by metric_cmp and optimize_plateau.
- CLI --select <argmax|plateau:mean|plateau:worst> (default argmax; unknown
token exits 2). walkforward_family dispatches via a select_winner helper;
sweep_over/stage1_r_sweep_over carry the lattice as Option<Vec<usize>>.
runs-family display gains a plateau(<mode>)=<score> over <n> cells line.
RandomSpace-refuse: walkforward has no --random producer, so the
plateau-without-lattice guard is structural — select_winner returns the
refuse on a None lattice (the caller prints the message and exits 2),
unit-tested at the helper, not via a --random E2E (decided + recorded on #145
comment 1974, with the lattice-seam fork).
Tests: plateau-picks-plateau-not-spike, mean-vs-worst, lower-is-better
direction-flip, closed-neighbourhood golden, single-member degeneracy, C1
determinism; CLI select-parse, select_winner refuse; E2E argmax-byte-identical
(C23), plateau:mean and plateau:worst provenance. Full workspace suite green;
clippy --all-targets -D warnings clean.
closes#145
Brummel
cb32658fd1