feat(desktop): 确定性昼夜光照过渡与夜灯暖光

新增 lightingBlend 纯函数（黎明明 4:00-6:00、暮色 20:00-22:00 线性过渡，边界与 isNightTick 对齐），天空底色/世界 tint 按混合插值渲染，夜晚灯笼暖光晕强度=LanternGlow（纯叠加矩形、无每帧分配风险）；回归测试含锚点/单调斜坡/确定性/光晕开关。

1 files changed, 15 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 1d50f3d..9464c8b 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -676,6 +676,21 @@ type LivingVillageGame() as this =
                 world.Tick
                 profile.WorldTint
 
+            // Warm lantern glows strengthen as night falls (pure function of tick phase).
+            if profile.LanternGlow > 0.3f then
+                let glow = profile.LanternGlow
+                let haloAlpha = int (90.0f * glow)
+                for prop in renderPlan.Props do
+                    match prop.Kind with
+                    | RiverLantern ->
+                        let position = VillageArt.worldTile renderPlan prop.Position
+                        let screenX = position.X * Sim.tilePixels - int camera.X + Sim.tilePixels / 2
+                        let screenY = position.Y * Sim.tilePixels - int camera.Y - Sim.tilePixels / 2
+                        spriteBatch.Draw(pixel, Rectangle(screenX - 22, screenY - 22, 60, 60), Color(252, 216, 148, int (float32 haloAlpha * 0.35f)))
+                        spriteBatch.Draw(pixel, Rectangle(screenX - 14, screenY - 14, 44, 44), Color(252, 216, 148, haloAlpha))
+                        spriteBatch.Draw(pixel, Rectangle(screenX - 8, screenY - 8, 32, 32), Color(255, 236, 180, haloAlpha))
+                    | _ -> ()
+
             let avatarSpec = VillageArt.avatarSpriteSpec avatarFacing world.Tick
             VillageArt.drawCharacter spriteBatch artTextures camera world.Avatar.Pos avatarSpec profile.WorldTint