Give Overpass POI downloads icons/descriptions and unique filenames

Overpass categories now carry the same icon+color styling a p4n2gpx
waypoint gets, instead of falling back to gpx.js's plain red marker,
plus a popup description built from opening_hours/operator/website
tags. Supermarket/convenience store reuse NPS's generic store glyph,
the only honest match in that icon set.

Each plugin run's saved filename now bakes in the area's center and a
timestamp, so repeated downloads for different areas land as separate,
identifiable files instead of overpass-pois.geojson/-1/-2/...

lib/maptool/overpass_pois.rb

@@ -14,23 +14,42 @@ module Maptool
 
     OVERPASS_API = "https://overpass-api.de/api/interpreter".freeze
 
-    # Each entry: an Overpass tag filter -> a human category label, used
-    # both to build the query (unioning every filter) and to label results
-    # back (matched by scanning an element's own tags for the same
+    # Each entry: an Overpass tag filter -> { label:, icon:, color: }, used
+    # both to build the query (unioning every filter) and to label/style
+    # results back (matched by scanning an element's own tags for the same
     # key/value, not by which branch of the query found it — Overpass's
-    # `out body` doesn't say which union member matched).
+    # `out body` doesn't say which union member matched). `icon` names one
+    # of the marker glyphs public/js/icons.js's POI_ICONS already vendors
+    # for the GPX/p4n upload path — reused here rather than drawn again —
+    # so these render the same way a p4n2gpx waypoint of the same kind
+    # does, instead of every point falling back to gpx.js's plain red
+    # unlabeled marker (its TRACK_COLOR default for a point with no color
+    # of its own). shop_supermarket/shop_convenience both point at the same
+    # NPS "store" glyph (icons.js's STORE_ICON) — that set has no separate
+    # grocery-specific pictogram, so this is the honest match for both.
     CATEGORIES = {
-      { "amenity" => "drinking_water" } => "Drinking water",
-      { "amenity" => "sanitary_dump_station" } => "Dump station",
-      { "amenity" => "fuel", "fuel:lpg" => "yes" } => "LPG refill",
-      { "shop" => "gas" } => "LPG refill",
-      { "amenity" => "toilets" } => "Public toilet",
-      { "shop" => "laundry" } => "Laundry",
-      { "shop" => "supermarket" } => "Supermarket",
-      { "shop" => "convenience" } => "Convenience store",
-      { "natural" => "spring" } => "Spring",
+      { "amenity" => "drinking_water" } => { label: "Drinking water", icon: "amenity_drinking_water", color: "#2e86de" },
+      { "amenity" => "sanitary_dump_station" } => { label: "Dump station", icon: "amenity_sanitary_dump_station", color: "#8d6e63" },
+      { "amenity" => "fuel", "fuel:lpg" => "yes" } => { label: "LPG refill", icon: "shop_gas", color: "#e67e22" },
+      { "shop" => "gas" } => { label: "LPG refill", icon: "shop_gas", color: "#e67e22" },
+      { "amenity" => "toilets" } => { label: "Public toilet", icon: "amenity_toilets", color: "#8d6e63" },
+      { "shop" => "laundry" } => { label: "Laundry", icon: "shop_laundry", color: "#5b9bd5" },
+      { "shop" => "supermarket" } => { label: "Supermarket", icon: "shop_supermarket", color: "#27ae60" },
+      { "shop" => "convenience" } => { label: "Convenience store", icon: "shop_convenience", color: "#27ae60" },
+      { "natural" => "spring" } => { label: "Spring", icon: "amenity_drinking_water", color: "#2e86de" },
     }.freeze
 
+    # Tags worth surfacing in a popup, beyond the bare category label —
+    # each rendered as its own "Label: value" line, which gpx.js's
+    # formatDescription (written for p4n2gpx's own "Label: value" export
+    # lines) already turns into a distinct row with no changes needed on
+    # that end. website/contact:website are emitted as a bare URL line
+    # instead, since formatDescription also already auto-links those.
+    DESCRIPTION_TAGS = [
+      ["opening_hours", "Opening hours"],
+      ["operator", "Operator"],
+    ].freeze
+
     # bbox: [south, west, north, east] (Overpass's own axis order).
     def self.fetch(bbox, timeout: 60)
       query = build_query(bbox, timeout: timeout)
@@ -59,12 +78,19 @@ module Maptool
       features = (overpass_response["elements"] || []).filter_map do |element|
         next unless element["type"] == "node"
 
-        category = category_for(element["tags"] || {})
+        tags = element["tags"] || {}
+        category = category_for(tags)
         next unless category
 
         {
           "type" => "Feature",
-          "properties" => { "name" => (element["tags"] || {})["name"] || category, "category" => category },
+          "properties" => {
+            "name" => tags["name"] || category[:label],
+            "category" => category[:label],
+            "icon" => category[:icon],
+            "color" => category[:color],
+            "description" => description_for(tags),
+          }.compact,
           "geometry" => { "type" => "Point", "coordinates" => [element["lon"], element["lat"]] },
         }
       end
@@ -72,11 +98,19 @@ module Maptool
     end
 
     def self.category_for(tags)
-      CATEGORIES.each do |filter, label|
-        return label if filter.all? { |k, v| tags[k] == v }
+      CATEGORIES.each do |filter, category|
+        return category if filter.all? { |k, v| tags[k] == v }
       end
       nil
     end
     private_class_method :category_for
+
+    def self.description_for(tags)
+      lines = DESCRIPTION_TAGS.filter_map { |tag, label| "#{label}: #{tags[tag]}" if tags[tag] }
+      website = tags["website"] || tags["contact:website"]
+      lines << website if website
+      lines.empty? ? nil : lines.join("\n")
+    end
+    private_class_method :description_for
   end
 end