p73: 昼夜光照四时段档（清晨/正午/黄昏/夜晚）

M6Presentation 新增 periodAtTick/periodLighting 参数表（AmbientTint 乘性色调 + Veil/VeilAlpha 加性覆盖 + LanternGlow），边界与 timePeriodLabel 一致；正午为恒等档不改白平衡。DrawWorldView 并入时段色调与 effectiveLanternGlow（黄昏 0.6 起点亮、夜晚 1.0），覆盖色最后叠加。新增 P73 回归；新增 LV_P73_SHOT 同机位四帧证据 + analyze-p73（verdict=PASS）；字形表补 正/午（345）。Desktop 346/346、Kernel 120/120、digest 与 p70 一致。

6 files changed, 45 insertions, 0 deletions

diff --git a/docs/evidence/p73-analysis.txt b/docs/evidence/p73-analysis.txt
new file mode 100644
index 0000000..a8a0243
--- /dev/null
+++ b/docs/evidence/p73-analysis.txt
@@ -0,0 +1,28 @@
+P73（昼夜光照层次：清晨/正午/黄昏/夜晚四档）证据分析 — 真实 Desktop xvfb 1280x720
+钩子：LV_P73_SHOT=1（同一桥头光源机位，6/12/18/22 各一帧，画面差异只来自光照）
+路径：tick → periodAtTick → periodLighting(环境色调/覆盖色/VeilAlpha/灯光) + 连续 blend/warmth veils
+
+p73-morning: hour=6.0 tick=1296000 period=清晨 blend=0.2 lantern=0.32 tint=(255, 229, 212) veil=20
+p73-noon: hour=12.0 tick=2592000 period=正午 blend=0.0 lantern=0.0 tint=(255, 255, 255) veil=0
+p73-dusk: hour=18.0 tick=3888000 period=黄昏 blend=0.0 lantern=0.6 tint=(255, 255, 255) veil=52
+p73-night: hour=22.0 tick=4752000 period=夜晚 blend=1.0 lantern=1.0 tint=(118, 136, 184) veil=26
+
+
+p73-morning.png: size=1280x720 brightness=107.9 R=123.0 G=118.7 B=81.8 warmth(R-B)=+41.2 std=34.1 dark_block=0
+p73-noon.png: size=1280x720 brightness=86.4 R=71.0 G=107.8 B=80.4 warmth(R-B)=-9.5 std=36.5 dark_block=0
+p73-dusk.png: size=1280x720 brightness=97.8 R=113.8 G=111.5 B=68.0 warmth(R-B)=+45.8 std=39.2 dark_block=0
+p73-night.png: size=1280x720 brightness=89.8 R=65.7 G=90.1 B=113.6 warmth(R-B)=-47.9 std=40.2 dark_block=0
+
+diff p73-morning vs p73-noon: differing_pixels=905809
+diff p73-morning vs p73-dusk: differing_pixels=905399
+diff p73-morning vs p73-night: differing_pixels=921390
+diff p73-noon vs p73-dusk: differing_pixels=905696
+diff p73-noon vs p73-night: differing_pixels=921368
+diff p73-dusk vs p73-night: differing_pixels=921390
+
+brightness order: morning(107.9) > dusk(97.8) > night(89.8) > noon(86.4)
+warmth order: dusk(+45.8) > morning(+41.2) > noon(-9.5) > night(-47.9)
+
+verdict=PASS
+  four periods have distinct parameters; noon identity, dusk lamps on, night lamps full;
+  real frames render 1280x720, differ pairwise, night darker / noon brighter / dusk warmer.
diff --git a/docs/evidence/p73-dusk.png b/docs/evidence/p73-dusk.png
new file mode 100644
index 0000000..1ad7fa4
--- /dev/null
+++ b/docs/evidence/p73-dusk.png
diff --git a/docs/evidence/p73-morning.png b/docs/evidence/p73-morning.png
new file mode 100644
index 0000000..1126d8b
--- /dev/null
+++ b/docs/evidence/p73-morning.png
diff --git a/docs/evidence/p73-night.png b/docs/evidence/p73-night.png
new file mode 100644
index 0000000..d7da3d8
--- /dev/null
+++ b/docs/evidence/p73-night.png
diff --git a/docs/evidence/p73-noon.png b/docs/evidence/p73-noon.png
new file mode 100644
index 0000000..2458546
--- /dev/null
+++ b/docs/evidence/p73-noon.png
diff --git a/docs/维护说明.md b/docs/维护说明.md
index 5fa87a4..9d27dd1 100644
--- a/docs/维护说明.md
+++ b/docs/维护说明.md
@@ -91,6 +91,23 @@ final_digest 固定 953775FAEB2FDDE97289491AA260BD8D390C571E48A7A13AD2CB6FB7124F
   `CharacterFeetSitOnTheTileGroundLine`；图像级 `scripts/check-no-white-blocks.py`
   对夜晚录帧断言不存在 ≥64×64、每通道 ≥250、alpha ≥250 的方块（P13 旧帧 42/69 命中，修复后 0 命中）。
 
+## 昼夜光照档（P73）
+
+- 既有 `lightingBlend`（0 白天→1 夜晚，dawn 4.0–6.5 / dusk 20.0–22.0）与 `transitionWarmth`
+  （晨曦/黄昏三角暖色峰）是**连续曲线**；P73 在其上再叠一层**四时段档**，填补 17:00–19:15
+  原本与正午无差的黄昏空档。两者都由 `world.Tick` 纯函数导出，Kernel 不参与。
+- `M6Presentation.periodAtTick`：边界与 `timePeriodLabel` 完全一致（<5 夜晚、<8 清晨、
+  <17 正午、<21 黄昏、否则夜晚）→ `Morning | Noon | Dusk | Night`。
+- `M6Presentation.periodLighting`：纯数据参数表，每档给 `AmbientTint`（乘性环境色调）、
+  `Veil`/`VeilAlpha`（加性覆盖色，经 `VillageArt.premultiply`）、`LanternGlow`（灯光强度）。
+  **正午档为恒等**（白 tint / `VeilAlpha=0` / 灯光 0），故既有正午白平衡不变。
+- 渲染接线（`Game.fs` `DrawWorldView`）：`worldTint = multiplyTint profile.WorldTint period.AmbientTint`；
+  `lanternGlow = effectiveLanternGlow tick`（连续曲线与时段档取大，黄昏 0.6 起灯笼点亮、夜晚 1.0）；
+  时段覆盖色在 golden/moon veil 之后最后叠上。HUD/室内界未改。
+- **回归**：`P73LightingTierTests`（四档两两不同、正午恒等、黄昏灯亮、夜晚灯满、时段边界与
+  `timePeriodLabel` 一致）。**证据**：`scripts/analyze-p73.py` 对 `LV_P73_SHOT=1`（同一桥头机位
+  6/12/18/22 四帧）断言参数一致 + 亮度/暖度可辨 + 两两 pixel diff，落 `docs/evidence/p73-*`。
+
 ## 性能基线命令
 
 ```bash