fix(render): A7 Fix D D-3/D-4 — two-path lighting (objects plain-Lambert+sun, EnvCell wrap+no-sun) (#140)

mesh_modern unified all meshes into one calc_point_light path: it applied the
bake's half-Lambert wrap to objects (lighting character backs from a torch behind
them) and added the sun to EnvCell building shells (warm facade wash). Retail
splits these: objects = hardware plain Lambert max(0,N.L) + sun; EnvCell walls =
baked wrap, dynamics only, NO sun (minimize_envcell_lighting). Add a per-draw
uLightingMode (WbDrawDispatcher=0 object, EnvCellRenderer=1 envcell) selecting the
angular term (wrap vs plain Lambert) and gating the sun. Per-light cap + D-1 clamp
unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/AcDream.App/Rendering/Wb/EnvCellRenderer.cs

@@ -877,6 +877,7 @@ public sealed unsafe class EnvCellRenderer : IDisposable
             // WB EnvCellRenderManager.cs:406-409: uniform state setup.
             _shader.SetInt("uRenderPass", (int)renderPass);
             _shader.SetInt("uFilterByCell", 0);
+            _shader.SetInt("uLightingMode", 1);   // A7 Fix D D-3/D-4: EnvCell bake (wrap points, no sun)
 
             // Phase U.4 ROOT-CAUSE FIX (cell-shell flicker / "transparent walls when
             // moving"): upload uViewProjection HERE rather than inheriting it from