feat(directions): keyless A→B directions with turn-by-turn steps and FLY (#564)

Supersedes #219 by @spcpza, ported onto the current component layout with fixes from review.

Verified before merge: format, package boundaries, unit suite, build, and the browser tracking suite; a browser harness for the change where one applies; adversarial review applied.

Co-authored-by: spcpza <[email protected]>

src/app/constructCatalog.js

@@ -8,6 +8,7 @@ import { createApplicationCctv } from './layers/cctv.js';
 import { createApplicationRadio } from './layers/radio.js';
 import { createApplicationTraffic } from './layers/traffic.js';
 import { createApplicationBikeshare } from './layers/bikeshare.js';
+import { createApplicationDirections } from './layers/directions.js';
 import { createApplicationInstallations } from './layers/militaryInstallations.js';
 import { createApplicationSatellites } from './layers/satellites.js';
 import { createApplicationLaunches } from './layers/rocketLaunches.js';
@@ -109,6 +110,7 @@ export function createApplicationCatalog({
         createApplicationCctv({ surface, source: sources.cctv }),
         createApplicationRadio({ surface, source: sources.radio }),
         createApplicationBikeshare({ source: sources.bikeshare }),
+        createApplicationDirections(),
         vessels,
         installations,
         createApplicationAwareness({

src/app/constructCatalog.test.mjs

@@ -38,7 +38,7 @@ test('catalogs construct distinct layers and classification from their supplied
     signal: b.signal,
     surface: fixtureSurface(b.signal),
   });
-  assert.equal(first.layers.length, 17);
+  assert.equal(first.layers.length, 18);
   assert.deepEqual(
     first.layers.map(({ id }) => id),
     second.layers.map(({ id }) => id),

src/app/layers/directions.js

@@ -0,0 +1,12 @@
+import { createApplicationDirectionsLayer } from '../../data/directions.js';
+
+/**
+ * Construct one Directions layer using the application scene owners.
+ *
+ * It takes no data source: a route is fetched from `/api/route` when the
+ * operator places both endpoints, so there is nothing to supply up front.
+ * @returns {object} A fresh layer instance for this catalog.
+ */
+export function createApplicationDirections() {
+  return createApplicationDirectionsLayer();
+}