Draw a LiveTrack session's planned course alongside the actual track

Garmin's own LiveTrack page already shows both when the activity was
started from a saved course — the session payload carries the course's
geoPoints right alongside the track points (LiveTrackClient found it
nested under the same React Query cache the session/points come from).

Rendered as a second, dashed LineString distinct from the actual
track's own line ("kind": "actual" vs "planned" on each GeoJSON
feature) — muted gray rather than matching Garmin's own purple-for-
planned, since this app's actual track is already purple and reusing
it would make the two indistinguishable.

test/test_livetrack_client.rb

@@ -16,6 +16,7 @@ class LiveTrackClientTest < Minitest::Test
     <script>self.__next_f.push([1,"6:[\\"$\\",\\"div\\",null,{}]"])</script>
     <script>self.__next_f.push([1,"9:{\\"session\\":{\\"sessionName\\":\\"Test Ride\\",\\"start\\":\\"2026-01-01T00:00:00Z\\",\\"end\\":\\"2026-01-01T01:00:00Z\\"}}"])</script>
     <script>self.__next_f.push([1,"10:{\\"unrelated\\":true,\\"nested\\":{\\"data\\":{\\"pages\\":[{\\"trackPoints\\":[{\\"position\\":{\\"lat\\":48.1,\\"lon\\":17.2},\\"dateTime\\":\\"2026-01-01T00:00:00Z\\",\\"totalDistanceMeters\\":\\"$undefined\\"},{\\"position\\":{\\"lat\\":48.2,\\"lon\\":17.3},\\"dateTime\\":\\"2026-01-01T00:01:00Z\\",\\"activityType\\":\\"CYCLING\\",\\"totalDistanceMeters\\":5000,\\"totalDurationSecs\\":600}]}]}}}"])</script>
+    <script>self.__next_f.push([1,"11:{\\"courses\\":[{\\"name\\":\\"40 km okruh\\",\\"geoPoints\\":[{\\"position\\":{\\"lat\\":48.05,\\"lon\\":17.35},\\"distanceMeters\\":0},{\\"position\\":{\\"lat\\":48.06,\\"lon\\":17.36},\\"distanceMeters\\":1000}]}]}"])</script>
     </body></html>
   HTML
 
@@ -70,6 +71,15 @@ class LiveTrackClientTest < Minitest::Test
     assert Maptool::LiveTrackClient.summarize(result)["active"]
   end
 
+  def test_finds_the_planned_course_alongside_the_actual_track
+    payloads = @client.send(:parse_payloads, FAKE_PAGE)
+    course = @client.send(:clean, @client.send(:search, payloads) { |n| n["courses"].first if n["courses"].is_a?(Array) && !n["courses"].empty? })
+
+    assert_equal "40 km okruh", course["name"]
+    assert_equal 2, course["geoPoints"].size
+    assert_in_delta 48.06, course["geoPoints"].last["position"]["lat"]
+  end
+
   def test_no_track_points_found_in_a_page_without_them
     points = @client.send(:search, @client.send(:parse_payloads, "<html></html>")) { |n| n["trackPoints"] if n["trackPoints"].is_a?(Array) }
     assert_nil points