feat(ui-lvgl): vector region packs, PBF input, region list

One .vpk file per region in /vmap (header, sorted index of tiles and
points, then the data), read in place with the index in PSRAM; loose
{dz}/{x}/{y}.vt/.vp files still work. osm_vector.py writes packs
(--pack/--name), reads OSM PBF extracts for a box (--pbf/--bbox, via
pyosmium) and picks label languages (--lang). Map tools > Vector regions
lists the packs on the card: show one on the map, delete it. No
on-device download: packs are made with the tool.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/companion_radio/ui-lvgl/UITask.cpp

@@ -2183,6 +2183,7 @@ static lv_obj_t* switchRow(lv_obj_t* parent, const char* text, const char* sub,
 #include "MapScreen.h"
 #include "NavMap.h"
 #include "MapAreas.h"
+#include "MapRegions.h"
 #include "HomeScreen.h"
 #include "ClockScreen.h"
 #include "RadioScreen.h"
@@ -3105,6 +3106,8 @@ extern "C" EMSCRIPTEN_KEEPALIVE void sim_open(const char* name) {
   if (!strcmp(name, "maptools")) { s_ui->navToolsPopup(); return; }
   if (!strcmp(name, "areasel")) { s_ui->areaSelectBegin(); return; }
   if (!strcmp(name, "areas")) { s_ui->mapAreasPopup(); return; }
+  if (!strcmp(name, "regions")) { s_ui->mapRegionsPopup(); return; }
+  if (!strcmp(name, "region0")) { s_ui->mapRegionPopup(0); return; }
   if (!strcmp(name, "advert")) { s_ui->advertPopup(); return; }
 }
 // Scrolls the screen's (or a popup's) main list by dy; returns what was left to scroll.