fix(api): expose /webhook/live-positions/track so map trail matches SPA path

The Live Positions SPA calls GET /webhook/live-positions/track, but the
read-API only exposed /webhook/vehicle-track. Clicking a vehicle to view its
1-hour trail therefore 404'd even after repointing N8N_BASE. Register the SPA's
actual path as a route alias to the same handler (vehicle-track kept as alias),
so the only frontend change remains the base URL. Docstring updated to match.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

dashboard_api_rev.py

@@ -16,7 +16,8 @@ is the base URL (the `N8N_BASE` constant in each dashboard SPA):
 
   GET  /webhook/live-positions?cost_centre=&acc_status=
        → { summary, geojson }   (reporting.fn_live_positions)
-  GET  /webhook/vehicle-track?vehicle_number=&hours=
+  GET  /webhook/live-positions/track?vehicle_number=&hours=
+       (alias: /webhook/vehicle-track)
        → GeoJSON Feature        (reporting.fn_vehicle_track)
   GET  /webhook/fleet-dashboard
        → { drivers, cost_centres, cities, vehicles }  (filter options)
@@ -117,6 +118,10 @@ def live_positions(cost_centre: str | None = None, acc_status: str | None = None
         )
 
 
+# `/webhook/live-positions/track` is the path the Live Positions SPA actually
+# calls; `/webhook/vehicle-track` is kept as an alias. Both hit the same handler
+# so the only frontend change is the base URL (N8N_BASE).
+@app.get("/webhook/live-positions/track")
 @app.get("/webhook/vehicle-track")
 def vehicle_track(vehicle_number: str | None = None, hours: int = 1):
     veh = _clean(vehicle_number)