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({