Note UX polish: pin marker, icon picker, fix Save button color

- The clicked location now stays marked (a plain maplibre-gl Marker,
  removed on save/cancel/deactivate) while the note form is open —
  before, nothing on the map showed where the pending note would land.
- POI_ICONS gains a dozen more symbols (water, dump station, toilets,
  playground, viewpoint, swimming, fishing, climbing, hiking, …) via
  Object.assign after PARK4NIGHT_TAGS' own icon constants are declared
  (they're below POI_ICONS in the file, so the literal itself can't
  reference them directly) — reused as real marker-badge glyphs, not
  just PARK4NIGHT_TAGS' inline description-tag icons. NoteSaveForm
  gets a picker grid for these, shown only for a Point note (a
  Measure-drawn line/polygon has no one spot for a badge).
- Fixed: .notes-panel__save's blue background was losing to
  .notes-panel__actions button's gray — same class-vs-class+element
  specificity trap .gpx-panel__action[hidden] already has a comment
  about elsewhere in this file. The button was never actually blue.

Verified live (properly simulating a logged-in session this time, via
Page.addScriptToEvaluateOnNewDocument rather than a post-load DOM
poke, since NotesControl's mount decision happens once, synchronously,
at page load): marker appears and clears correctly, 19 icons + "none"
render and select, Save renders #1a5fb4. Full suite: 115 runs, 0
failures.

public/js/icons.js

@@ -305,6 +305,29 @@ export const PARK4NIGHT_TAGS = {
   windsurf: { icon: WIND_SURFING_ICON, label: "Windsurfing" },
 };
 
+// Extends POI_ICONS (and so POI_ICON_KEYS, and what a marker badge can
+// show — see gpx.js's _registerCategoryGlyphs) with a handful of the same
+// symbols PARK4NIGHT_TAGS above already vendors, reused rather than
+// duplicated — this app's own hand-drawn notes (notes.js's icon picker)
+// need marker-badge glyphs for "water source"/"dump station"/"viewpoint"
+// far more than the original OSM-POI-upload set (parking/hotel/fuel) ever
+// covered. Object.assign, not more entries in the POI_ICONS literal
+// itself, since these constants are declared below it in this file.
+Object.assign(POI_ICONS, {
+  amenity_drinking_water: DRINKING_WATER_ICON,
+  amenity_sanitary_dump_station: SANITARY_DISPOSAL_ICON,
+  amenity_toilets: RESTROOMS_ICON,
+  shop_gas: PROPANE_ICON,
+  amenity_electricity: ELECTRICAL_HOOKUP_ICON,
+  shop_laundry: LAUNDRY_ICON,
+  leisure_playground: PLAYGROUND_ICON,
+  tourism_viewpoint: SCENIC_VIEWPOINT_ICON,
+  leisure_swimming: SWIMMING_ICON,
+  leisure_fishing: FISHING_ICON,
+  sport_climbing: CLIMBING_ICON,
+  route_hiking: WALKING_ICON,
+});
+
 export const LIVETRACK_ICON = `
 <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round">
   <path d="M12 21s7-7.58 7-12a7 7 0 0 0-14 0c0 4.42 7 12 7 12z"/>