Detailed graphics pass: authored textures, humanoid NPCs, HUD feedback, asset pipeline

- tools/generate_textures.py (deterministic PIL) produces all authored PNGs:
  brick facade, concrete, asphalt, awning, skyline, vignette, HUD icons,
  access-card art (all <=1024px, power-of-two)
- WorldBuilder: textured facade/glass door/sidewalk/asphalt, striped awning
  with 'STEP LINE', generated skyline backdrop planes
- GameManager: soft sun shadows (4-split parallel); guard in 'guard' group
- NPC avatars: humanoid rig (torso/head/limbs) with archetype props (camera,
  delivery box, performer hat, protest sign, tourist backpack), procedural
  walk bob, head-turns-toward-guard attention cue
- HUD: inspection artifact cards, mode icons (flashlight/door/wand),
  per-escalation vignette, body-camera overlay (corner brackets + REC + clock)
- assets/ import convention documented; test_asset_textures_present_and_pow2
  guards the pipeline (57 tests pass)
- README tech stack updated for Gitea Actions + asset pipeline; screenshot
  gallery regenerated (day + night)

src/game/game_manager.gd

@@ -142,6 +142,7 @@ func _build_guard() -> GuardController:
 	collider.shape = shape
 	collider.position = Vector3(0, 0.85, 0)
 	g.add_child(collider)
+	g.add_to_group("guard")
 	return g
 
 func _build_scenario(id: String) -> VenueScenario:
@@ -197,6 +198,10 @@ func _ensure_lighting() -> void:
 	_sun.name = "Sun"
 	_sun.rotation_degrees = Vector3(-50, -30, 0)
 	_sun.light_energy = 1.2
+	_sun.shadow_enabled = true
+	_sun.light_angular_distance = 1.2
+	_sun.directional_shadow_mode = DirectionalLight3D.SHADOW_PARALLEL_4_SPLITS
+	_sun.directional_shadow_max_distance = 60.0
 	scene_root.add_child(_sun)
 	_env_node = WorldEnvironment.new()
 	var env := Environment.new()
@@ -398,6 +403,7 @@ func _cycle_venue() -> void:
 	switch_scenario(VENUE_ORDER[_venue_index])
 	var venue_name: String = selected_scenario.display_name if selected_scenario else "?"
 	hud.log(Strings.fmt("hud.venue_switched", [venue_name]))
+	hud.set_wand_icon(false)
 	hud.set_shift_state(coordinator, selected_scenario)
 
 ## Aim-free targeting: cycle through NPCs near the guard (Tab). Lets players
@@ -548,11 +554,14 @@ func _toggle_inspection() -> void:
 func _toggle_wand_screening() -> void:
 	if wand_open:
 		hud.hide_wand()
+		hud.set_wand_icon(false)
 		wand_open = false
 		return
 	if not selected_scenario.equipment.has("wand"):
 		hud.log(Strings.lookup("hud.no_wand"))
+		hud.set_wand_icon(false)
 		return
+	hud.set_wand_icon(true)
 	var controller: Object = _targeted_controller()
 	if controller == null:
 		return