Tree Navigator

The Navigator has two surfaces.

1. Canonical Layer/DAG Map

This is the primary UI. It mirrors the registered runtime architecture:

• L0-L8 main flow;

• L1.5-L4.5 diagnostic side branches;

• graph mode for L3, L4, and L7;

• list mode for setup, construction list layers, diagnostics, evaluation, tests, and output;

• sink handoffs between registered layers.

Click a layer card to inspect:

• role and category;

• expected upstream sinks;

• produced sinks;

• sub-layers;

• layer globals;

• axes or output controls.

Graph/DAG layers do not have one flat axis list. Their decisions live in YAML nodes, params, inputs, and sinks. The UI now exposes clickable DAG items and writes a runnable YAML template from the selected layer axes plus selected DAG items.

Canonical Sub-Layers

The layer map should expose every main and diagnostic sub-layer below. If a sub-layer is absent in the UI, treat that as a UI bug rather than a design change.

Layer	UI mode	Sub-layers
L0	list	L0.A Execution policy
L1	list	L1.A Source selection; L1.B Target definition; L1.C Predictor universe; L1.D Geography scope; L1.E Sample window; L1.F Horizon set; L1.G Regime definition
L2	list	L2.A FRED-SD frequency alignment; L2.B Transform; L2.C Outlier handling; L2.D Imputation; L2.E Frame edge
L3	graph	L3.A Target construction; L3.B Feature pipelines; L3.C Pipeline combine; L3.D Feature selection
L4	graph	L4.A Model selection; L4.B Forecast strategy; L4.C Training window; L4.D Tuning
L5	list	L5.A Metrics; L5.B Benchmark; L5.C Aggregation; L5.D Slicing and decomposition; L5.E Ranking
L6	list	L6 globals; L6_A_equal_predictive; L6_B_nested; L6_C_cpa; L6_D_multiple_model; L6_E_density_interval; L6_F_direction; L6_G_residual
L7	graph	L7.A Importance DAG; L7.B Output shape
L8	list	L8_A_export_format; L8_B_saved_objects; L8_C_provenance; L8_D_artifact_granularity
L1.5	list	L1.5.A Sample coverage; L1.5.B Univariate summary; L1.5.C Stationarity; L1.5.D Missing and outlier; L1.5.E Correlation; L1.5.Z Export
L2.5	list	L2.5.A Comparison; L2.5.B Distribution shift; L2.5.C Correlation shift; L2.5.D Cleaning summary; L2.5.Z Export
L3.5	list	L3.5.A Comparison; L3.5.B Factor inspection; L3.5.C Feature correlation; L3.5.D Lag inspection; L3.5.E Selection; L3.5.Z Export
L4.5	list	L4.5.A Fit; L4.5.B Scale; L4.5.C Window stability; L4.5.D Tuning; L4.5.E Ensemble; L4.5.Z Export

YAML Generation Contract

The YAML preview is generated from the canonical workbench, not the legacy compatibility explorer.

• List layers write fixed_axes from selected sub-layer axes.

• Layer-global controls, including diagnostic enabled, are selectable and written into YAML.

• Graph layers write template DAGs with nodes, inputs, params, and sinks.

• Clicked DAG items are stored in leaf_config.navigator_selected_dag_items so the YAML records the graph design choices that shaped the template.

• Multi-select axes write YAML lists.

The generated YAML is intended as a valid starting recipe. Advanced graph editing can still refine node IDs, custom leaf config, and model-specific parameters after download.

2. Compatibility Axis Explorer

The lower explorer is retained for option-level compatibility checks. It shows enabled/disabled choices, disabled reasons, path effects, and YAML preview. It still contains some historical axis-group labels because it is a compatibility surface, not the canonical architecture view.

Use it after choosing a canonical layer when you need to know why a specific option is blocked.

Reading The UI

UI element	Meaning
Main flow cards	Canonical L0-L8 execution order.
Diagnostic side branches	Default-off hooks that consume construction sinks and produce diagnostics.
DAG badge	Layer is configured as a graph of source/step/sink nodes.
List badge	Layer is configured by ordered sub-layers and axes.
Sink handoffs	Registry-derived edges from produces to expected_inputs.
Runtime support	Current runtime support class for selected options.

Boundary Rule

The layer map is authoritative for architecture. The compatibility explorer is useful for individual option constraints, but old labels in that explorer should not override the canonical layer IDs.