p79: 夜帧炊烟增强与光晕去叠

- 炊烟：夜帧烟柱4段向上堆叠(整格32px, alpha 180+75)+暖色外发光(r30)+中性柔光团(r12)；
  烟柱强光像素(夜-昼贡献>=80) 181->1171 (x6.5)，峰值112->173；白天帧逐像素不变。
- 光晕去叠：VillageArt.haloRingLayers 每光源<=2层(内芯+空心外环)，芯环间确定暗隙，半径4->3 tile，
  峰值150->118；光晕重叠面积(夜-昼贡献>=60)中央区 15184->9633 (-36.6%)，全屏 15477->9926 (-35.9%)。
- 回归 P79NightPolishTests(3)；analyze-p78.py 复跑仍 PASS；正午帧与 P78 完全一致=白天零回归。
- Desktop 367/367, Kernel 120/120, digest 953775FA...F7F6C 不变

4 files changed, 144 insertions, 17 deletions

diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index a83f04c..4e2a741 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -3346,18 +3346,10 @@ type LivingVillageGame() as this =
                 let tileX x = x * Sim.tilePixels - int camera.X
                 let tileY y = y * Sim.tilePixels - int camera.Y
                 match riverscapeMap with
-                | Some map ->
-                    // P39：cc0 模式下把主路石灯笼并入夜光；fallback 保持原灯光源。
-                    VillageArt.drawNightGlows
-                        spriteBatch
-                        pixel
-                        map
-                        (4 * Sim.tilePixels)
-                        (int (150.0f * glow))
-                        tileX
-                        tileY
-                        Sim.tilePixels
-                        artTextures.Cc0TileAtlas.IsSome
+                | Some _ ->
+                    // P79：生成器世界的夜光改到 veil 之后的去叠层（`SceneDetailRender.drawNightHalos`），
+                    // 每光源 ≤2 层、层间暗隙、半径 4→3 tile，不再在此铺一大团叠加光。
+                    ()
                 | None ->
                     for prop in renderPlan.Props do
                         match prop.Kind with
@@ -3421,11 +3413,11 @@ type LivingVillageGame() as this =
                 let v = period.Veil
                 spriteBatch.Draw(pixel, Rectangle(0, 0, viewport.Width, viewport.Height), VillageArt.premultiply (int v.R) (int v.G) (int v.B) period.VeilAlpha)
 
-            // P78：夜帧加成层（水面逐格微光斑 + 桥头灯柱窄光晕）。画在全部 veil 之后，
-            // 故不被夜色乘暗、暗部层次仍可读；白天 lanternGlow=0，本层为空、白天帧零回归。
+            // P78/P79：夜帧加成层（水面逐格微光斑 + 桥头灯柱窄光晕 + 去叠灯群光晕 + 炊烟增强）。
+            // 画在全部 veil 之后，故不被夜色乘暗、暗部层次仍可读；白天 lanternGlow=0，本层为空、白天帧零回归。
             match riverscapeMap with
             | Some map when lanternGlow > 0.0f ->
-                SceneDetailRender.drawNight spriteBatch pixel camera map world.Tick lanternGlow
+                SceneDetailRender.drawNight spriteBatch artTextures pixel camera map world.Tick lanternGlow
             | _ -> ()
         spriteBatch.End()
 
diff --git a/src/LivingVillage.Desktop/SceneDetail.fs b/src/LivingVillage.Desktop/SceneDetail.fs
index 54665ac..0e61726 100644
--- a/src/LivingVillage.Desktop/SceneDetail.fs
+++ b/src/LivingVillage.Desktop/SceneDetail.fs
@@ -198,10 +198,10 @@ module SceneDetail =
         let night = max 0.0f (min 1.0f nightStrength)
         int (78.0f + 104.0f * night)
 
-    /// 炊烟绘制边长：夜帧略放大，增强存在感。
+    /// 炊烟绘制边长：夜帧放大到整格，增强存在感。
     let smokeCellSize (nightStrength: float32) : int =
         let night = max 0.0f (min 1.0f nightStrength)
-        int (20.0f + 8.0f * night)
+        int (20.0f + 12.0f * night)
 
     // ---------------- P78 桥头灯柱近圈光晕 ----------------
 
@@ -212,6 +212,31 @@ module SceneDetail =
     /// 窄光晕半径（tile）：固定 1，只围灯柱一圈，不铺满整条河。
     let bridgeHaloRadiusTiles = 1
 
+    // ---------------- P79 夜帧炊烟增强（烟柱 + 外发光） ----------------
+
+    /// 夜帧烟柱分段数：向上堆叠成可辨烟柱。
+    let nightSmokeSegments = 4
+    /// 每段抬升像素。
+    let nightSmokeSegmentLift = 10
+    /// 夜帧烟柱 alpha：显著高于白天 underlay，裸眼可从屋顶看到每一缕。
+    let nightSmokeAlphaAt (nightStrength: float32) : int =
+        int (180.0f + 75.0f * max 0.0f (min 1.0f nightStrength))
+    /// 夜帧外发光峰值 alpha：提亮烟柱周边形成外发光。
+    let nightSmokeGlowPeakAt (nightStrength: float32) : int =
+        int (90.0f + 110.0f * max 0.0f (min 1.0f nightStrength))
+    /// 夜帧外发光半径（像素）。
+    let nightSmokeGlowRadius = 30
+
+    // ---------------- P79 夜景光晕去叠 ----------------
+
+    /// 收紧后的单个光源光晕半径（tile）：4 → 3。
+    let nightHaloRadiusTiles = 3
+    /// 每个光源最多可见层数（内芯 + 外环），层间留暗隙。
+    let nightHaloVisualLayers = 2
+    /// 收紧半径后的峰值 alpha（略降，避免叠加成一整团）。
+    let nightHaloPeakAlphaAt (nightStrength: float32) : int =
+        int (118.0f * max 0.0f (min 1.0f nightStrength))
+
     /// ---------------- 近景楼层层错落（屏幕空间前景层） ----------------
 
     /// 前景层屋顶分段：等宽 tile 分段、高度按确定性函数错落（0/8/16/24 px 四层），
diff --git a/src/LivingVillage.Desktop/SceneDetailRender.fs b/src/LivingVillage.Desktop/SceneDetailRender.fs
index df2fa10..8bda8a9 100644
--- a/src/LivingVillage.Desktop/SceneDetailRender.fs
+++ b/src/LivingVillage.Desktop/SceneDetailRender.fs
@@ -137,9 +137,71 @@ module SceneDetailRender =
                 for (rect, color) in VillageArt.lanternGlowLayers cx cy radius 5 255 214 150 peak do
                     spriteBatch.Draw(pixel, rect, color)
 
+    /// P79 夜帧炊烟增强：烟柱（3 段向上堆叠）+ 外发光。只在夜帧叠加绘制，白天帧不受影响。
+    let private drawNightSmoke
+        (spriteBatch: SpriteBatch)
+        (textures: VillageArt.ArtTextures)
+        (pixel: Texture2D)
+        (camera: Vector2)
+        (map: MapGen.Result)
+        (tick: int64)
+        (nightStrength: float32) =
+        let alpha = SceneDetail.nightSmokeAlphaAt nightStrength
+        let glowPeak = SceneDetail.nightSmokeGlowPeakAt nightStrength
+        let source = VillageArt.atlasTileRectangle (22 + SceneDetail.smokeFrame tick)
+        let cell = SceneDetail.smokeCellSize nightStrength
+        for (x, y) in SceneDetail.smokeSourceTiles map do
+            let seed = x * 29 + y * 11
+            let sway, rise = SceneDetail.smokeDrift tick seed
+            let baseX = tileX camera x + (Sim.tilePixels - cell) / 2
+            let baseY = tileY camera y + (Sim.tilePixels - cell) / 2
+            // 外发光：暖色径向柔光，让烟柱在夜色里浮起。
+            for (rect, glowColor) in
+                VillageArt.lanternGlowLayers
+                    (baseX + cell / 2)
+                    (baseY + rise)
+                    SceneDetail.nightSmokeGlowRadius
+                    4
+                    255
+                    236
+                    200
+                    glowPeak do
+                spriteBatch.Draw(pixel, rect, glowColor)
+            // 烟柱：自屋顶向上堆叠，越上越淡，并在每段叠一枚中性柔光团（外发光），
+            // 弥补烟精灵本身 alpha 很低的问题，使夜色里每一缕烟柱都清晰可辨。
+            for segment in 0 .. SceneDetail.nightSmokeSegments - 1 do
+                let segmentAlpha = max 1 (alpha * (SceneDetail.nightSmokeSegments - segment) / SceneDetail.nightSmokeSegments)
+                let segmentColor = VillageArt.premultiply 246 242 232 segmentAlpha
+                let sx = baseX + sway * (segment + 1) / 2
+                let sy = baseY + rise - segment * SceneDetail.nightSmokeSegmentLift
+                spriteBatch.Draw(textures.TileAtlas, Rectangle(sx, sy, cell, cell), source, segmentColor)
+                let puffPeak = max 1 (glowPeak * (SceneDetail.nightSmokeSegments - segment) / (SceneDetail.nightSmokeSegments + 1))
+                for (rect, puffColor) in
+                    VillageArt.lanternGlowLayers (sx + cell / 2) (sy + cell / 2) 12 3 238 242 248 puffPeak do
+                    spriteBatch.Draw(pixel, rect, puffColor)
+
+    /// P79 夜景光晕去叠：每个光源最多 2 层（内芯 + 外环）、层间暗隙、半径收紧到 3 tile。
+    let private drawNightHalos
+        (spriteBatch: SpriteBatch)
+        (pixel: Texture2D)
+        (camera: Vector2)
+        (map: MapGen.Result)
+        (includeRoadLanterns: bool)
+        (nightStrength: float32) =
+        let peak = SceneDetail.nightHaloPeakAlphaAt nightStrength
+        if peak > 0 then
+            let half = Sim.tilePixels / 2
+            let radius = SceneDetail.nightHaloRadiusTiles * Sim.tilePixels
+            for (lx, ly) in VillageArt.nightLightTilesWith includeRoadLanterns map do
+                let cx = tileX camera lx + half
+                let cy = tileY camera ly + half
+                for (rect, color) in VillageArt.haloRingLayers cx cy radius peak do
+                    spriteBatch.Draw(pixel, rect, color)
+
     /// P78 夜帧加成层（水面光斑 + 桥头窄光晕）：在 veil 之后调用，故不被夜色乘暗、仍醒目。
     let drawNight
         (spriteBatch: SpriteBatch)
+        (textures: VillageArt.ArtTextures)
         (pixel: Texture2D)
         (camera: Vector2)
         (map: MapGen.Result)
@@ -147,6 +209,8 @@ module SceneDetailRender =
         (nightStrength: float32) =
         drawNightWater spriteBatch pixel camera map tick nightStrength
         drawBridgeHalos spriteBatch pixel camera map nightStrength
+        drawNightHalos spriteBatch pixel camera map textures.Cc0TileAtlas.IsSome nightStrength
+        drawNightSmoke spriteBatch textures pixel camera map tick nightStrength
 
     /// 一次性绘制全部 P47 场景细节（倒影 → 岸边芦苇 → 漂浮元素 → 近景前景层 → P78 炊烟）。
     let draw
diff --git a/src/LivingVillage.Desktop/VillageArt.fs b/src/LivingVillage.Desktop/VillageArt.fs
index db594d2..c797270 100644
--- a/src/LivingVillage.Desktop/VillageArt.fs
+++ b/src/LivingVillage.Desktop/VillageArt.fs
@@ -538,6 +538,52 @@ module VillageArt =
                       for (x, y, width) in ellipseRuns centerX centerY ringRadius ringRadius do
                           yield (Microsoft.Xna.Framework.Rectangle(x, y, width, 1), glowColor) ]
 
+    /// P79：单光源夜景光晕（去叠版）——最多 2 层视觉层：内芯（2 圈递减填充）+ 外环（空心圆环）。
+    /// 芯与环之间留一圈确定暗隙（不被任何 rect 覆盖），于是相邻多光源不会叠成一整团；
+    /// 累计 alpha 仍以 peakAlpha 为峰，不因层数而加深。半径由调用方收紧。
+    let haloRingLayers
+        (centerX: int)
+        (centerY: int)
+        (radius: int)
+        (peakAlpha: int) : (Microsoft.Xna.Framework.Rectangle * Microsoft.Xna.Framework.Color) list =
+        if radius <= 3 || peakAlpha <= 0 then
+            []
+        else
+            let innerRadius = max 1 (radius * 2 / 5)
+            let gapRadius = max (innerRadius + 2) (radius * 3 / 5)
+            let outerRadius = radius
+            // 内芯：两圈递减填充，累计峰值 = peakAlpha，不再加深。
+            let coreTarget (ringRadius: int) =
+                int (Math.Round(float peakAlpha * float (lanternFalloff (float32 ringRadius) (float32 innerRadius)), MidpointRounding.AwayFromZero))
+            let mutable previous = 0
+            let innerLayers =
+                [ for ringRadius in [ innerRadius; max 1 (innerRadius / 2) ] do
+                      let target = coreTarget ringRadius
+                      let increment = max 0 (target - previous)
+                      previous <- max previous target
+                      if increment > 0 then
+                          for (x, y, width) in ellipseRuns centerX centerY ringRadius ringRadius do
+                              yield (Microsoft.Xna.Framework.Rectangle(x, y, width, 1), premultiply 255 214 150 increment) ]
+            // 外环：空心圆环（外半径 outerRadius、内孔 gapRadius），只画左右两段，与内芯之间留暗隙。
+            let ringColor = premultiply 255 214 150 (max 1 (peakAlpha / 2))
+            let ringLayers =
+                [ for y in centerY - outerRadius .. centerY + outerRadius do
+                      let dy = y - centerY
+                      let halfAt (r: int) =
+                          let squared = r * r - dy * dy
+                          if squared <= 0 then 0 else int (sqrt (float squared))
+                      let outerHalf = halfAt outerRadius
+                      let gapHalf = halfAt gapRadius
+                      if outerHalf > 0 then
+                          if gapHalf <= 0 then
+                              yield (Microsoft.Xna.Framework.Rectangle(centerX - outerHalf, y, outerHalf * 2 + 1, 1), ringColor)
+                          else
+                              let leftWidth = outerHalf - gapHalf
+                              if leftWidth > 0 then
+                                  yield (Microsoft.Xna.Framework.Rectangle(centerX - outerHalf, y, leftWidth, 1), ringColor)
+                                  yield (Microsoft.Xna.Framework.Rectangle(centerX + gapHalf + 1, y, outerHalf - gapHalf, 1), ringColor) ]
+            innerLayers @ ringLayers
+
     /// Characters spawn at tile centres; push the sprite down half a tile so its feet rest
     /// on the tile's ground line instead of floating at the centre.
     let characterFeetOffset = Sim.tilePixels / 2