Detail the NPC avatars and finish the realism follow-ups

Blender library
- Rebuild the face: sclera, iris and upper lid per eye, brow ridge, cheekbones,
  nose bridge and tip, ears with lobes, split upper/lower lips.
- Give each hand four fingers plus a thumb and end every sleeve in a cuff ring.
- Raise CHAR_MAX_VERTS 4000 -> 5000 (16 avatars still cost ~6.9 ms of a 50 ms
  frame), decimate the body to 26 %; characters are now 3,974-5,026 tris and
  3,744-4,807 verts. Rebuild all 8 variants and re-bake their AO maps.

Capture tooling
- Add a `portrait` stage to capture_realism.gd: freeze one NPC, park the crowd
  out of frame, stand the subject on open sidewalk, turn it into the camera and
  put the guard on the sunlit side. New --portrait-type=N picks the role.
- Add the npc_portrait_day concept and map the shot to it, so avatar detail is
  scored against a portrait instead of a wide street frame.

Flashlight
- Drop the fake additive beam (Materials.light_beam + the cone mesh): on GL
  Compatibility a first-person camera inside the cone renders it as a filled
  disc with a bright far ring. Keep the tight spot (14 deg, 20 m, energy 4.2)
  and its headless test; the visible shaft is now planned behind a Forward+
  preset.

Docs and task tracking
- Move the finished realism follow-ups (ground exposure, flashlight, NPC detail,
  judge re-check) to DONE.md and expand TODO.md with step-by-step plans for NPC
  gear fit, venue geometry plus the committed gallery, and the Forward+ preset.
- Record the decisions, gotchas and portrait recipe in MEMORY.md; update the
  Blender contract, the concept README and the capture section of README.md.
- Refresh the gallery captures affected by the avatar rebuild.

Checks: headless 228/228, Python 86/86, blender_assets audit exit 0,
scene_concepts audit all GOOD, screen_designs compare 11 good / 0 bad,
smoke_npc_budget OK, boot clean (only the known headless mesh warning).

src/game/materials.gd

@@ -128,35 +128,6 @@ static func emissive(color: Color, energy: float = 1.4) -> StandardMaterial3D:
 	mat.roughness = 0.4
 	return mat
 
-## Fake light shaft for the flashlight (Compatibility has no volumetrics).
-## Additive, unshaded, no depth write: it glows over the scene, is still occluded
-## by walls, and fades out along its length instead of ending in a hard disc.
-static func light_beam() -> StandardMaterial3D:
-	var mat := StandardMaterial3D.new()
-	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
-	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
-	mat.blend_mode = BaseMaterial3D.BLEND_MODE_ADD
-	mat.cull_mode = BaseMaterial3D.CULL_DISABLED
-	mat.depth_draw_mode = BaseMaterial3D.DEPTH_DRAW_DISABLED
-	mat.albedo_color = Color(1.0, 0.95, 0.82, 1.0)
-	# A vertical ramp, not a GradientTexture1D: a cylinder's UV.y runs along its
-	# height, while the 1D gradient varies with U and would paint a bright ring.
-	var ramp := Image.create(1, 64, false, Image.FORMAT_RGBA8)
-	for y in 64:
-		var t := float(y) / 63.0
-		# Symmetric fade (bright in the middle, gone at both ends) so the look
-		# does not depend on which way CylinderMesh orients its V coordinate; the
-		# far end must never show as a bright ring.
-		var alpha := 0.0
-		if t < 0.5:
-			alpha = lerpf(0.0, 0.3, t / 0.5)
-		else:
-			alpha = lerpf(0.3, 0.0, (t - 0.5) / 0.5)
-		ramp.set_pixel(0, y, Color(1.0, 1.0, 1.0, alpha))
-	mat.albedo_texture = ImageTexture.create_from_image(ramp)
-	mat.texture_filter = BaseMaterial3D.TEXTURE_FILTER_LINEAR
-	return mat
-
 ## Dark glass for windows and the entrance door. The alpha keeps the interior
 ## visible, and the low roughness gives the facade a highlight instead of a hole.
 static func glass(color: Color = Color(0.42, 0.56, 0.72, 0.75)) -> StandardMaterial3D: