fix(prototype): count driving lanes from laneConfigs, require moving leader

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mod/content/overtake_probe.script.tl

@@ -47,10 +47,13 @@ local function rebuildable(seg : integer) : boolean, string
 	local be = api.engine.getComponent(seg, api.type.ComponentType.BASE_EDGE) as Engine.Component.BaseEdge
 	if be == nil then return false, "no BaseEdge" end
 	if #be.objects > 0 then return false, "has edge objects" end
-	local tn = api.engine.getComponent(seg, api.type.ComponentType.TRANSPORT_NETWORK) as Engine.Component.TransportNetwork
+	-- count BaseEdge lanes, not TransportNetwork edges (town roads split each lane into several edges).
+	-- Sidewalks carry modes 0/1 only; driving lanes carry 2+ (observed: [2,3,4]).
 	local driving = 0
-	for _, e in ipairs(tn.edges) do
-		if e.speedLimit > 0 then driving = driving + 1 end
+	for _, lc in ipairs(be.laneConfigs) do
+		for k, on in pairs(lc.transportModes) do
+			if on and (tonumber(tostring(k)) or 0) >= 2 then driving = driving + 1 break end
+		end
 	end
 	if driving ~= 2 then return false, "driving lanes=" .. driving end
 	return true, string.format("template=%s length=%.1f", tostring(be.roadTemplate), be.distance)
@@ -116,7 +119,8 @@ local function dump(dt : number, state : GameScriptState<ProbeState>)
 				local a, b = cars[i], cars[j]
 				-- ponytail: assumes pos grows in driving direction when dir=true (held so far in the logs)
 				local ahead = (a.dir and b.pos > a.pos) or (not a.dir and b.pos < a.pos)
-				if i ~= j and ahead and math.abs(b.pos - a.pos) < MAX_GAP then
+				-- leader must be moving, otherwise it's a queue at a stop or junction, not a slow vehicle
+				if i ~= j and ahead and math.abs(b.pos - a.pos) < MAX_GAP and b.speed > 1.0 then
 					local seg = laneSeg[key]
 					local ok, why = rebuildable(seg)
 					p(string.format("REBUILD_TEST candidate seg=%d follower=%d (pos=%.1f v=%.2f) leader=%d (pos=%.1f v=%.2f) ok=%s %s",