Add crowd presentation, fix NPC navigation, refresh screenshots

NPC navigation (previously dead in the live game)
- Only assign NavigationAgent3D.target_position when it changes: re-assigning every
  frame invalidated the path, so get_next_path_position() kept returning the current
  point and avatars never moved.
- Follow the first path point that is closer to the destination than the avatars are.
  Nav points sit on the navmesh plane (y=0) while bodies stand at y~0.5, so the old
  3D distance test always looked "already there"; path[0] is also the old start point,
  so a naive "far enough away" pick steered backwards and oscillated.
- Fix fsm.state -> fsm.current_state in the idle-lifetime check.

Crowd presentation
- Aggressive behavior, visible weapons, and responder arrivals make idle bystanders
  stop and face the incident for 12 s; someone waiting at the entrance keeps focus.
- Panic (mood >= 0.75) walks people away from the door at 2.4 m/s, then they despawn.
- Wire reactions to EventBus.crowd_changed: CrowdSystem.apply_event() emits on the bus,
  not on its own `changed` signal (the first wiring received nothing).
- Measured a 16-NPC entrance at ~1.2 ms/frame (824 fps, vsync off), so no LOD/culling.

World and HUD
- Skyline is now a ring of four alpha-scissored planes at 200 m instead of a single
  plane; PlaneMesh defaults to horizontal, which is why the backdrop rendered as a band
  overhead. Larger ground plane, mipmapped texture, scissor threshold 0.5 (0.3 left
  mip dashes in the sky), lifted albedo so the city is not pure black.
- Flashlight aims straight ahead and lights the person/door instead of the ground.
- Shorter HUD controls line so it stops overlapping itself.

Tests, tooling, docs
- Headless suite 98 -> 105 (new test_crowd_presentation.gd, 7 tests).
- New smoke_crowd.gd: rubbernecking, panic, and flee-target sanity.
- capture_screenshots.gd starts a shift from the venue menu and stages the night set
  properly; all six README screenshots regenerated.
- README, TODO/DONE (crowd section moved), MEMORY updated. Version 0.2.4.

src/test/tests/test_crowd_presentation.gd

@@ -0,0 +1,106 @@
+extends RefCounted
+## Crowd presentation: rubbernecking on aggressive/emergency events and clearing
+## out when the crowd panics (PLAN: Public Crowd Reaction).
+
+const CrowdSystem := preload("res://src/core/crowd_system.gd")
+const NpcAvatar := preload("res://src/game/npc_avatar.gd")
+const NpcProfile := preload("res://src/core/npc_profile.gd")
+const Rules := preload("res://src/core/rules.gd")
+
+func _profile() -> NpcProfile:
+	var p := NpcProfile.new()
+	p.id = "bystander"
+	p.display_name = "Bystander"
+	p.npc_type = Rules.NpcType.TOURIST
+	return p
+
+func _avatar() -> Node:
+	var avatar: Node = NpcAvatar.new()
+	avatar.setup(_profile(), "photo", 99, Vector3(4, 0.5, 8), Vector3(2, 0.5, 12))
+	return avatar
+
+func test_reaction_for_event() -> bool:
+	var a := TestUtils.check_eq(CrowdSystem.reaction_for_event("aggressive_behavior"), "watch", "aggression draws watchers")
+	var b := TestUtils.check_eq(CrowdSystem.reaction_for_event("emergency_responder"), "watch", "responder draws watchers")
+	var c := TestUtils.check_eq(CrowdSystem.reaction_for_event("visible_weapon"), "watch", "a weapon draws watchers")
+	var d := TestUtils.check_eq(CrowdSystem.reaction_for_event("de_escalation"), "", "de-escalation is not a watch cue")
+	var e := TestUtils.check_eq(CrowdSystem.reaction_for_event("calm_professionalism"), "", "calm is not a watch cue")
+	return a and b and c and d and e
+
+func test_panic_flag_and_flee_cue() -> bool:
+	var crowd := CrowdSystem.new()
+	var a := TestUtils.check(not crowd.should_flee(), "crowd starts calm")
+	crowd.apply_event("visible_weapon")
+	crowd.apply_event("aggressive_behavior")
+	crowd.apply_event("aggressive_behavior")
+	crowd.apply_event("emergency_responder")
+	var b := TestUtils.check(crowd.should_flee(), "stacked alarms reach panic")
+	var c := TestUtils.check_eq(crowd.summary().get("panic"), true, "summary reports panic")
+	var calm := CrowdSystem.new()
+	calm.apply_event("de_escalation")
+	calm.apply_event("calm_professionalism")
+	var d := TestUtils.check(not calm.should_flee(), "a calm crowd does not flee")
+	crowd = null
+	calm = null
+	return a and b and c and d
+
+func test_idle_bystander_rubbernecks() -> bool:
+	var avatar := _avatar()
+	# Still walking: should refuse so traffic is not frozen mid-approach.
+	var walking := TestUtils.check(not avatar.start_rubberneck(Vector3(0, 1, 1)), "walkers keep walking")
+	avatar.arrived = true
+	var accepted := TestUtils.check(avatar.start_rubberneck(Vector3(0, 1, 1)), "idle bystander watches")
+	var mode := TestUtils.check_eq(avatar.reaction_mode, "watch", "watch mode is set")
+	var active := TestUtils.check(avatar.reaction_is_active(), "reaction is active")
+	avatar.free()
+	return walking and accepted and mode and active
+
+func test_engaged_person_does_not_rubberneck() -> bool:
+	var avatar := _avatar()
+	avatar.arrived = true
+	avatar.awaiting_interaction = true
+	# Not in a tree, so use local position (global_position is a no-op here).
+	avatar.position = avatar.door_position
+	var ok := TestUtils.check(not avatar.start_rubberneck(Vector3.ZERO), "someone waiting at the door does not rubberneck")
+	# The same person further away is an ordinary bystander and does watch.
+	avatar.position = avatar.door_position + Vector3(8, 0, 0)
+	var far_ok := TestUtils.check(avatar.start_rubberneck(Vector3.ZERO), "a bystander away from the door still watches")
+	avatar.free()
+	return ok and far_ok
+
+func test_panic_moves_people_away_from_the_door() -> bool:
+	var avatar := _avatar()
+	avatar.position = Vector3(1, 0.5, 2)
+	var door := Vector3(0, 0.5, 1.2)
+	avatar.start_flee(door)
+	var a := TestUtils.check_eq(avatar.reaction_mode, "flee", "flee mode is set")
+	var b := TestUtils.check((avatar.target_position - door).length() > (avatar.position - door).length(),
+		"flee target is farther from the door than the start")
+	var c := TestUtils.check(not avatar.awaiting_interaction, "fleeing cancels waiting at the entrance")
+	avatar.free()
+	return a and b and c
+
+func test_crowd_updates_arrive_through_the_event_bus() -> bool:
+	## CrowdSystem.apply_event() emits EventBus.crowd_changed, not its own
+	## `changed` signal; wiring the wrong one silently disables crowd reactions.
+	var src := FileAccess.get_file_as_string("res://src/game/game_manager.gd")
+	var ok := TestUtils.check(src.contains("event_bus.crowd_changed.connect(_on_crowd_changed)"),
+		"GameManager listens on EventBus.crowd_changed")
+	var bus: Object = load("res://src/core/event_bus.gd").new()
+	var seen: Array = []
+	bus.crowd_changed.connect(func(payload): seen.append(payload.get("event", "")))
+	var crowd := CrowdSystem.new()
+	crowd.set_event_bus(bus)
+	crowd.apply_event("aggressive_behavior")
+	var delivers := TestUtils.check_eq(seen, ["aggressive_behavior"], "apply_event reaches the bus listener")
+	bus = null
+	crowd = null
+	return ok and delivers
+
+func test_leaving_npc_does_not_flee() -> bool:
+	var avatar := _avatar()
+	avatar.npc.leave_requested = true
+	avatar.start_flee(Vector3.ZERO)
+	var ok := TestUtils.check_eq(avatar.reaction_mode, "", "someone already leaving is left alone")
+	avatar.free()
+	return ok