Test plan — Routing (#136)

Use download #3, FarmersKornerTest-fastroute.img. Its routable trail network was moved out of the road-dense Farmers Korner area (which gave "route calculation error" / "no routes found") into the roadless Tenmile Range ~4.5 km west, and the trails are set to max speed / road class so the router should prefer them.

Pan west to ≈ 39.554 N, −106.100 W. The trails are a Y-junction of orange 3px lines — Main Trail + East Spur + South Spur — meeting at 39.5540, −106.1000. ⚠️ Remove #1/#2 from GARMIN/ first (same map ID).

Step 1 — Does it route on our trail at all?

Navigate to a trail endpoint (Navigate → Coordinates, or pan + select the point + Go):

South Spur end	`39.5512, −106.0995`
East Spur end	`39.5534, −106.0977`
Main Trail end	`39.5558, −106.1020`
Junction (Y)	`39.5540, −106.1000`

☐ Does it compute a route without error this time (no "route calculation error" / "no routes found")?
☐ Does the route line follow the orange trail to the endpoint, rather than straight-lining?

Step 2 — Turn-by-turn through the junction

Route from the Main Trail end (39.5558, −106.1020) to the South Spur end (39.5512, −106.0995) — the only path is Main Trail → junction → South Spur.

☐ Does it give a turn instruction at the Y (onto South Spur)? That's the shared junction node working.
☐ Does it report distance to the next junction?

Record the verdict

turn-by-turn (follows trail + junction distance) / point-nav only (straight line) / still errors. If it works now, the earlier failures were basemap-density confusion, not a defect.

Note: this build changed two things at once (location + trail speed). If it routes, we can follow up with a moved-but-normal-speed build to see which mattered. Reference: docs/experimental-features-spikes.md Phase 3.