Document multi-warning Brīdinājumi selection and chip restyle

docs/UPDATE_ROADMAP.md

@@ -133,10 +133,12 @@ Status: pending
 - [x] Add a separate Latvian-named Brīdinājumi workspace that renders current LVĢMC warning polygons without manual tracing.
 - [x] Add production border overlay artwork and feathered warning-polygon fills to Brīdinājumi.
 - [x] Replace Brīdinājumi's 4-corner bounding-box projection with an affine fit calibrated against the same validated Kartes/Faktiskā city pixel positions.
-- [x] Limit the Brīdinājumi canvas to one operator-selected warning, remove the on-canvas legend, collapse card detail to phenomenon/severity by default with full detail on click, and pre-fill the title from the selected warning's phenomenon.
+- [x] Limit the Brīdinājumi canvas to one operator-selected warning (superseded below by multi-warning selection), remove the on-canvas legend, collapse card detail to phenomenon/severity by default with full detail on click, and pre-fill the title from the selected warning's phenomenon.
 - [x] Redesign Brīdinājumi warning cards as compact phenomenon-icon chips and move full warning text into a dialog popup over a dimmed, blurred backdrop.
 - [x] Give Brīdinājumi chips a hover state where the severity-colored icon capsule expands to fill the chip, adapted from a reviewed external Uiverse.io reference component.
 - [x] Split Brīdinājumi's warning selection (checkbox, drives the map) from viewing a warning's detail (clicking the chip, opens the popup) so choosing a map warning no longer forces the popup open; widen the detail popup for readability.
+- [x] Replace single-warning selection with multi-select checkboxes so combined-severity newsroom maps (e.g. yellow + orange wind together) can be produced; re-add severity-ordered compositing of every checked warning's polygons. Restyle chips as narrower, fully severity-colored, white-icon/white-text buttons, and port a reviewed Uiverse.io checkbox component for the selection control.
+- [ ] Decide whether Brīdinājumi should actively prevent checking warnings of different phenomena together, or continue leaving that as an operator responsibility.
 - [ ] Tune Brīdinājumi feather-blur bleed at sharp coastline curves (e.g. the Gulf of Rīga indentation).
 - [ ] Test target resolutions and real workplace display conditions.
 - [ ] Check keyboard navigation, contrast, focus states, and screen-reader labeling.
@@ -213,3 +215,4 @@ Record completed work here by date and commit after the Git workflow is establis
 | 2026-08-22 | `cafc75a` | Redesign Brīdinājumi warning cards as compact phenomenon-icon chips and move full warning text into a dialog popup over a dimmed, blurred backdrop | Yes — Rocky typecheck, build, and headless-browser screenshot verification of the popup open/close flow; VPS deployment pending |
 | 2026-08-22 | `70fd24c` | Give Brīdinājumi chips a hover-expanding severity capsule, adapted from a reviewed Uiverse.io reference component | Yes — Rocky typecheck, build, and headless-browser screenshot verification of rest/hover/active chip states; VPS deployment pending |
 | 2026-08-22 | `6fbf672` | Split Brīdinājumi warning selection (checkbox) from viewing detail (chip click) and widen the detail popup | Yes — Rocky typecheck, build, and headless-browser verification that checkbox clicks change the map selection without opening the popup and chip clicks open the correct warning's detail without changing the selection; VPS deployment pending |
+| 2026-08-22 | `56b8716` | Replace single-warning Brīdinājumi selection with multi-select checkboxes and severity-ordered polygon compositing, and restyle chips as narrower, fully severity-colored, white-icon/white-text buttons with a ported Uiverse.io checkbox component | Yes — Rocky typecheck, build, and headless-browser screenshot verification of multiple simultaneous checked warnings compositing correctly on the map; VPS deployment pending |