Revert texture tinting by the lit-color plane -- it double-colours

Found my own prior documentation (IG-SHADING-MODEL.md sec 2, written earlier
this session before compaction) that already establishes: the wire's 0x1a
texture uploads arrive ALREADY colourised (the material ramp is pre-baked on
this path, per the shipped libDPL header model cross-referenced against
BT411's context/rendering.md). Tinting them again with the lit-color plane
double-colours the result -- exactly the "more colors but neither correct"
outcome reported live (sky/ground now differ, but neither right).

Keep the lit-color plane for FLAT (untextured) polys only, where it replaces
a hardcoded placeholder with real per-polygon data; textured polys sample
unmodified, as documented. The underlying r24/g24/b24 mechanism itself is
still real and worth understanding precisely (see open-questions tracking),
but applying it as a texture tint was the wrong model.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

emulator/firmware-decomp/emu860c/gpu_raster.py

@@ -176,9 +176,13 @@ class Renderer:
         tid = raw[..., 4].view(np.float32).astype(np.int64)
         hasuv = raw[..., 5].view(np.float32)
         # lit color (dvpx_r24/g24/b24 -> TREEclmpintoMEM): the polygon's
-        # computed lighting, clamped to [0,255] -- see build_prims. Used as
-        # the direct color for flat polys, and as a multiplicative tint on
-        # sampled texture color for textured ones.
+        # computed lighting, clamped to [0,255] -- see build_prims. Used ONLY
+        # for flat (untextured) polys. NOT applied to textured polys: per
+        # IG-SHADING-MODEL.md sec 2 (established from IG-board ground truth
+        # BEFORE this session's misstep), the wire's 0x1a texture uploads
+        # arrive ALREADY colourised (the ramp is pre-baked on this path) --
+        # tinting them again double-colours, which is exactly the "more
+        # colors but neither correct" result the user reported live.
         lit = np.stack([raw[..., 6].view(np.float32),
                         raw[..., 7].view(np.float32),
                         raw[..., 8].view(np.float32)], axis=-1)
@@ -204,6 +208,5 @@ class Renderer:
             # texture, so full-frame sampling here was O(ntex x W x H))
             ui = wrap_index((ucoord[sel] * tu) >> 8, tu, wrap_u)
             vi = wrap_index((vcoord[sel] * tv) >> 8, tv, wrap_v)
-            samp = arr[vi, ui].astype(np.float64) * (lit[sel] / 255.0)
-            composite_masked(img, sel, np.clip(samp, 0, 255).astype(np.uint8), cut_mode)
+            composite_masked(img, sel, arr[vi, ui], cut_mode)
         return img