v3.31.0 — one checkbox for CONUS/Alaska layer pairs

One panel checkbox can now drive several layers, for variables that ship as separate CONUS and Alaska rasters. Opt-in; no config changes needed otherwise.

Toggle groups (#349, #390)

• New asset-level toggle_group. Layers sharing a value get one panel row, labelled with the value, whose checkbox shows and hides every member. Members can come from different collections.
• Members stay separate layers. Each keeps its own source, colormap/rescale, layer_id and legend, so CONUS and Alaska can keep different stretches. The agent can still show one half alone; the row's checkbox then shows as indeterminate.
• Versioned members share one dropdown over all their labels. Picking a label switches every member that has it. A member without that label is hidden and named on the row ("2024 not available for: …"), and comes back when a label it has is picked.
• Identical legends merge. Visible members whose legends would draw the same thing (same classes and colours, or same colormap, range and units) share one legend entry titled with the group name. Different stretches keep separate colorbars.

See "Toggle groups" in the configuration guide.

Upgrading

Drop-in from v3.30.x. Without toggle_group, behaviour is unchanged.

Full changelog: v3.30.2...v3.31.0