Integrate the Blender character, gear and prop library

NpcAvatar
- select one of 8 library character variants by role/seed (with npc_base and the
  procedural rig as fallbacks), keep Rig/Head and the existing bone animation
- tint only skin/cloth/pants/accessory/hair; fixed detail materials keep their
  colour, npc_vest keeps its hi-vis vest, firefighter/guard use dark uniform tints
- attach caps, hoods, helmets, backpacks, SCBA tanks, lanyards and hand items at
  the documented head/back/chest/hand points (primitive fallbacks retained)

WorldBuilder
- prefer assets/models/blender/props/ for the six replacements and the new
  street dressing (street lamp/tree, palms, planters, A-frame, cone, barrier,
  stanchion, podium, handrail, wall lantern, double door, marquee, sedan)
- fit the same colliders/navigation obstacles and keep the placement validator;
  collect library emissives (bulbs, marquee face, wall lanterns, door LED, sedan
  lights) for set_night_mode()
- add a library triangle counter + 60k budget check (current ~27,986); toggle
  prop gallery to the library models; fix the marquee label placement

Tests/smoke
- character selection/gear attach/fixed-material tint tests; library prop load,
  emissive and triangle-budget tests; smoke_props routes a guest around a
  stanchion in open sidewalk (the old bench route is now crowded by trees)
- headless 222/222, Python 68/68, all smokes pass, compare 11 good / 0 bad

Docs: TODO Phase 3.5 moved to DONE, README/architecture/blender-assets/plan
describe the integrated runtime, MEMORY records the integration rules.

src/test/capture_prop_gallery.gd

@@ -7,6 +7,7 @@ extends SceneTree
 
 const OUT_DIR := "user://screenshots"
 const MODEL_DIR := "res://assets/models/generated/"
+const LIBRARY_DIR := "res://assets/models/blender/props/"
 const PROPS := ["bollard", "bench", "trash_bin", "planter_box",
 	"newspaper_box", "fire_hydrant"]
 const SPACING := 1.9
@@ -74,7 +75,10 @@ func _build_stage() -> void:
 	var columns := [-1.95, 0.0, 1.95]
 	for index in PROPS.size():
 		var prop_name: String = PROPS[index]
-		var packed := ResourceLoader.load(MODEL_DIR + prop_name + ".glb") as PackedScene
+		var path := LIBRARY_DIR + prop_name + ".glb"
+		if not ResourceLoader.exists(path):
+			path = MODEL_DIR + prop_name + ".glb"
+		var packed := ResourceLoader.load(path) as PackedScene
 		if packed == null:
 			continue
 		var model := packed.instantiate() as Node3D

src/test/smoke_props.gd

@@ -19,6 +19,7 @@ var failures: Array[String] = []
 var bench: Node3D = null
 var bench_center := Vector3.ZERO
 var bench_body: StaticBody3D = null
+var route_center := Vector3.ZERO
 var guard_start := Vector3.ZERO
 var npc: Node3D = null
 var npc_start := Vector3.ZERO
@@ -46,12 +47,12 @@ func _process(_delta: float) -> bool:
 			_find_bench()
 			if bench == null:
 				return false
-			# Stand a couple of metres in front of the bench and walk into it.
-			var start := bench_center + Vector3(0, 0, 2.2)
+			# Stand on the door side of the bench and walk into it (+z). The
+			# street side is crowded with trees/planters now.
+			var start := bench_center - Vector3(0, 0, 2.0)
 			start.y = 0.1
 			gm.guard.global_position = start
-			# Face the bench (-z): yaw 0 looks down -z, so W walks toward it.
-			gm.guard.rotation.y = 0.0
+			gm.guard.rotation.y = PI
 			guard_start = start
 			Input.action_press("move_forward")
 			step = 1
@@ -59,9 +60,9 @@ func _process(_delta: float) -> bool:
 		1:
 			if step_frame >= GUARD_PUSH_FRAMES:
 				Input.action_release("move_forward")
-				_check(guard_start.z - gm.guard.global_position.z > 0.5,
+				_check(gm.guard.global_position.z - guard_start.z > 0.5,
 					"guard walked toward the bench")
-				_check(gm.guard.global_position.z > bench_center.z + 0.25,
+				_check(gm.guard.global_position.z < bench_center.z - 0.25,
 					"guard stopped at the bench instead of passing through it")
 				_check(not _inside_bench(gm.guard.global_position),
 					"guard is not inside the bench collider")
@@ -71,16 +72,14 @@ func _process(_delta: float) -> bool:
 				step = 2
 				step_frame = 0
 		2:
-			if step_frame % 120 == 0 and npc != null and is_instance_valid(npc):
-				print("npc dbg pos=%s vel=%s arrived=%s wait=%s" % [str(npc.global_position), str(npc.velocity), str(npc.arrived), str(npc.awaiting_interaction)])
 			if npc == null or not is_instance_valid(npc):
 				_stage_npc()
 				return false
 			if _npc_finished():
-				_check(npc.global_position.z < bench_center.z - 0.4,
-					"guest reached the far side of the bench")
-				_check(not _inside_bench(npc.global_position),
-					"guest is not inside the bench collider")
+				_check(npc.global_position.z > route_center.z + 0.35,
+					"guest reached the far side of the stanchion")
+				_check(npc.global_position.distance_to(route_center) > 0.4,
+					"guest is not inside the stanchion collider")
 				_check(npc_start.distance_to(npc.global_position) > 1.0,
 					"guest moved while routing around the prop")
 				_finish()
@@ -112,22 +111,33 @@ func _stage_npc() -> void:
 		step = 0
 		step_frame = 0
 		return
+	var detail := root.find_child("StreetDetail", true, false)
+	route_center = bench_center
+	if detail != null:
+		for child in detail.get_children():
+			if str(child.name).begins_with("Prop_stanchion"):
+				route_center = (child as Node3D).global_position
+				break
 	npc = gm.npcs[0]
-	npc_start = bench_center + Vector3(0, 0.5, 2.5)
+	npc_start = route_center + Vector3(0, 0.5, -2.0)
 	npc.global_position = npc_start
 	npc.velocity = Vector3.ZERO
 	npc.arrived = false
 	npc.awaiting_interaction = false
 	npc.lifetime_s = 999.0
 	npc.reaction_mode = ""
-	# Target well past the bench forces a straight line through it, and stays
-	# beyond the controller's 3 m "arrived" shortcut so the guest must route.
-	npc.target_position = Vector3(bench_center.x, 0.5, bench_center.z - 5.0)
+	if npc.npc != null:
+		# "enter" would send the guest to the door once the path ends; keep this
+		# test focused on routing around the prop.
+		npc.npc.intent = "roam"
+	# A stanchion sits in open sidewalk, so the route is not squeezed by trees
+	# or bins; the target forces a straight line through it.
+	npc.target_position = Vector3(route_center.x, 0.5, route_center.z + 5.5)
 
 func _npc_finished() -> bool:
 	if npc == null or not is_instance_valid(npc):
 		return false
-	return npc.global_position.z < bench_center.z - 0.4 \
+	return npc.global_position.z > route_center.z + 0.35 \
 		or npc.global_position.distance_to(npc.target_position) < 0.9
 
 func _inside_bench(point: Vector3) -> bool:

src/test/tests/test_generated_props.gd

@@ -201,6 +201,38 @@ func test_fallback_props_get_the_same_collider() -> bool:
 	root.free()
 	return a and b and c and d
 
+func test_world_loads_the_blender_library_props() -> bool:
+	var root := Node3D.new()
+	var builder := WorldBuilder.new(root)
+	builder.build()
+	var a := TestUtils.check(builder.fallback_props.is_empty(),
+		"no primitive prop fallback (fallbacks: %s)" % str(builder.fallback_props))
+	var b := TestUtils.check(builder.library_props.has("street_lamp")
+		and builder.library_props.has("street_tree")
+		and builder.library_props.has("bollard")
+		and builder.library_props.has("palm_tree")
+		and builder.library_props.has("sedan"),
+		"replacement and new props come from the library (%d)" % builder.library_props.size())
+	var c := TestUtils.check(root.get_node_or_null("Building/LibraryDoubleDoor") != null
+		and root.get_node_or_null("LibraryMarquee") != null
+		and root.get_node_or_null("ParkedSedan") != null,
+		"library door, marquee and sedan are placed")
+	var d := TestUtils.check(not builder._lamp_bulb_mats.is_empty()
+		and not builder._marquee_emissive.is_empty(),
+		"library lamps/marquee expose emissive materials")
+	builder.set_night_mode(true)
+	var lit := (builder._lamp_bulb_mats[0].emission_energy_multiplier > 0.0
+		and builder._marquee_emissive[0].emission_energy_multiplier > 0.0)
+	builder.set_night_mode(false)
+	var dark := builder._lamp_bulb_mats[0].emission_energy_multiplier <= 0.0
+	var e := TestUtils.check(lit and dark, "night mode drives library emissives")
+	var triangles := builder.library_triangle_count()
+	var f := TestUtils.check(triangles > 0
+		and triangles <= WorldBuilder.LIBRARY_TRIANGLE_BUDGET,
+		"library prop triangles stay inside the budget (%d)" % triangles)
+	root.free()
+	return a and b and c and d and e and f
+
 func test_world_facade_windows_light_at_night() -> bool:
 	var root := Node3D.new()
 	var builder := WorldBuilder.new(root)

src/test/tests/test_npc_character.gd

@@ -128,7 +128,7 @@ func test_walk_to_idle_animation_transition() -> bool:
 func test_skinned_model_loads_and_keeps_the_head_contract() -> bool:
 	var avatar := _avatar(Rules.NpcType.TOURIST, 33)
 	var a := TestUtils.check(avatar.loaded_model and not avatar.fallback_avatar,
-		"committed npc_base.glb is used")
+		"a skinned library character is used")
 	var b := TestUtils.check(avatar.get_node_or_null("Rig/Head") != null,
 		"Rig/Head survives the skinned path")
 	var c := TestUtils.check(avatar._skeleton != null and avatar._bone_indices.has("Head")
@@ -137,6 +137,82 @@ func test_skinned_model_loads_and_keeps_the_head_contract() -> bool:
 	avatar.free()
 	return a and b and c
 
+func test_character_selection_is_deterministic_and_complete() -> bool:
+	var expected := {
+		Rules.NpcType.TOURIST: "npc_casual",
+		Rules.NpcType.CONFUSED_VISITOR: "npc_casual",
+		Rules.NpcType.INTOXICATED: "npc_casual",
+		Rules.NpcType.AUTHORIZED_STAFF: "npc_jacket",
+		Rules.NpcType.PROTESTER: "npc_jacket",
+		Rules.NpcType.INFLUENCER: "npc_coat",
+		Rules.NpcType.PERFORMER: "npc_dress",
+		Rules.NpcType.DELIVERY: "npc_vest",
+		Rules.NpcType.RESPONDER: "npc_firefighter",
+		Rules.NpcType.MENTAL_CRISIS: "npc_hoodie",
+	}
+	var problems: Array[String] = []
+	for npc_type in expected:
+		var model := NpcAvatar.character_model_for(npc_type, 5)
+		if model != expected[npc_type]:
+			problems.append("%d -> %s (expected %s)" % [npc_type, model, expected[npc_type]])
+		if not ResourceLoader.exists(NpcAvatar.BLENDER_NPC_DIR + model + ".glb"):
+			problems.append("%s missing" % model)
+		if NpcAvatar.character_model_for(npc_type, 5) != model:
+			problems.append("%d is not seed-stable" % npc_type)
+	# Seed-alternating variants still resolve to a library model.
+	for seed_value in [1, 2, 3, 4, 5, 6]:
+		var variant := NpcAvatar.character_model_for(Rules.NpcType.TRESPASSER, seed_value)
+		if not ResourceLoader.exists(NpcAvatar.BLENDER_NPC_DIR + variant + ".glb"):
+			problems.append("trespasser seed %d -> %s missing" % [seed_value, variant])
+	return TestUtils.check(problems.is_empty(),
+		"every role selects an existing library character (%s)" % str(problems))
+
+func test_library_gear_attaches_to_the_contract_points() -> bool:
+	var tourist := _avatar(Rules.NpcType.TOURIST, 12)
+	var backpack := tourist.find_child("Gear_backpack", true, false) as Node3D
+	var camera := tourist.find_child("Gear_camera", true, false) as Node3D
+	var a := TestUtils.check(tourist.character_model == "npc_casual"
+		and backpack != null and backpack.get_parent() is Node3D
+		and backpack.get_parent().name == "Rig",
+		"backpack attaches under Rig")
+	var b := TestUtils.check(camera != null and camera.get_parent() is Node3D
+		and camera.get_parent().name == "Hand",
+		"hand gear attaches under the hand proxy")
+	tourist.free()
+	var responder := _avatar(Rules.NpcType.RESPONDER, 12)
+	var helmet := responder.find_child("Gear_firefighter_helmet", true, false) as Node3D
+	var tank := responder.find_child("Gear_scba_tank", true, false) as Node3D
+	var flashlight := responder.find_child("Gear_flashlight", true, false) as Node3D
+	var c := TestUtils.check(responder.character_model == "npc_firefighter"
+		and helmet != null and helmet.get_parent().name == "Head",
+		"firefighter helmet attaches to Rig/Head")
+	var d := TestUtils.check(tank != null and flashlight != null,
+		"responder gets SCBA tank and flashlight")
+	responder.free()
+	return a and b and c and d
+
+func test_fixed_detail_materials_are_not_tinted() -> bool:
+	var avatar := _avatar(Rules.NpcType.RESPONDER, 3)
+	var mi := avatar.find_child("npc_base", true, false) as MeshInstance3D
+	var unknown_overrides := 0
+	var contract_overrides := 0
+	for index in mi.mesh.get_surface_count():
+		var source := mi.mesh.surface_get_material(index)
+		if source == null:
+			continue
+		var slot := str(source.resource_name)
+		var override := mi.get_surface_override_material(index)
+		if slot in ["skin", "cloth", "pants", "accessory", "hair"]:
+			if override != null:
+				contract_overrides += 1
+		elif override != null:
+			unknown_overrides += 1
+	var a := TestUtils.check(contract_overrides == 5, "five contract slots are tinted")
+	var b := TestUtils.check(unknown_overrides == 0,
+		"fixed detail materials keep their authored colour (%d overrides)" % unknown_overrides)
+	avatar.free()
+	return a and b
+
 func test_skinned_outfit_tints_the_material_slots() -> bool:
 	var avatar := _avatar(Rules.NpcType.TOURIST, 44)
 	var mi := avatar.find_child("npc_base", true, false) as MeshInstance3D