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/capture_screenshots.gd

@@ -31,6 +31,10 @@ func _process(_delta: float) -> bool:
 			quit(1)
 			return true
 	if gm != null and not camera_staged:
+		# The game boots into the venue menu now; start the Hollywood shift first.
+		var menu = gm.get("start_menu")
+		if menu != null and menu.visible:
+			gm.call("_on_venue_selected", "hollywood_building")
 		gm.guard.global_position = Vector3(0, 0.1, 10.5)
 		gm.guard.rotation.y = 0.0
 		gm.guard.head.rotation.x = deg_to_rad(2.0)
@@ -52,7 +56,8 @@ func _advance() -> void:
 				state = 1
 				state_frames = 0
 		1:
-			# Wait for a nearby NPC so the interaction HUD has a target.
+			# Wait for a nearby NPC so the interaction HUD has a target. NPCs now
+			# walk in from the street, so this can take a few simulated seconds.
 			if gm != null and gm.npcs.size() > 0:
 				gm.call("_cycle_nearby_target")
 				_face_target()
@@ -83,24 +88,27 @@ func _advance() -> void:
 				# Close the radio form, then jump the shift to the LATE phase.
 				if gm != null:
 					gm.radio_panel.hide()
-					gm.guard.rotation.y = 0.0
-					gm.guard.head.rotation.x = deg_to_rad(2.0)
+					gm.hud.set_action_hint("")
 					gm.coordinator.elapsed_s = 750.0
 				state = 5
 				state_frames = 0
 		5:
-			# Let the phase transition (and street lamps / marquee) settle, then
-			# take the night avenue shot.
+			# Stage the avenue view down the boulevard (not into the wall) and let
+			# the night lighting and street lamps settle.
+			if state_frames == 1 and gm != null:
+				gm.guard.rotation.y = deg_to_rad(-70)
+				gm.guard.head.rotation.x = deg_to_rad(3.0)
 			if state_frames >= 90:
-				gm.guard.rotation.y = 0.0
-				gm.guard.head.rotation.x = deg_to_rad(2.0)
 				_shoot("05-late-night-avenue.png")
-				if gm != null:
-					gm.call("_toggle_flashlight")
 				state = 6
 				state_frames = 0
 		6:
-			if state_frames >= 40:
+			# Face the entrance again and switch the flashlight on for the night set.
+			if state_frames == 1 and gm != null:
+				gm.guard.rotation.y = 0.0
+				gm.guard.head.rotation.x = deg_to_rad(4.0)
+				gm.call("_toggle_flashlight")
+			if state_frames >= 30:
 				_shoot("06-night-flashlight.png")
 				state = 7
 				quit(0)