Enhanced sky atmosphere with DBC-driven colors, sun lighting, and zone weather

- Skybox now uses DBC sky colors (skyTop/skyMiddle/skyBand1/skyBand2) instead
  of hardcoded C++ color curves, with 3-band gradient and Rayleigh/Mie scattering
- Clouds receive sun direction for lit edges, self-shadowing, and silver lining
- Fixed sun quad box artifact with proper edge fade in celestial shader
- Lens flare attenuated by fog, cloud density, and weather intensity
- Replaced garish green/purple lens flare ghosts with warm natural palette
- Added zone-based weather system for single-player mode with per-zone rain/snow
  configuration, probability-based activation, and smooth intensity transitions
- Server SMSG_WEATHER remains authoritative when connected to a server

include/rendering/skybox.hpp

@@ -9,6 +9,7 @@ namespace wowee {
 namespace rendering {
 
 class VkContext;
+struct SkyParams;
 
 /**
  * Skybox renderer
@@ -16,6 +17,9 @@ class VkContext;
  * Renders an atmospheric sky gradient using a fullscreen triangle.
  * No vertex buffer: 3 vertices cover the entire screen via gl_VertexIndex.
  * World-space ray direction is reconstructed from the inverse view+projection.
+ *
+ * Sky colors are driven by DBC data (Light.dbc / LightIntBand.dbc) via SkyParams,
+ * with Rayleigh/Mie atmospheric scattering for realistic appearance.
  */
 class Skybox {
 public:
@@ -27,12 +31,12 @@ public:
     void recreatePipelines();
 
     /**
-     * Render the skybox
+     * Render the skybox using DBC-driven sky colors.
      * @param cmd Command buffer to record into
      * @param perFrameSet Per-frame descriptor set (set 0, contains camera UBO)
-     * @param timeOfDay Time of day in hours (0-24), affects sky color
+     * @param params Sky parameters with DBC colors and sun direction
      */
-    void render(VkCommandBuffer cmd, VkDescriptorSet perFrameSet, float timeOfDay = 12.0f);
+    void render(VkCommandBuffer cmd, VkDescriptorSet perFrameSet, const SkyParams& params);
 
     /**
      * Enable/disable skybox rendering
@@ -58,15 +62,7 @@ public:
      */
     void update(float deltaTime);
 
-    /**
-     * Get horizon color for fog (public for fog system)
-     */
-    glm::vec3 getHorizonColor(float time) const;
-
 private:
-    glm::vec3 getSkyColor(float altitude, float time) const;
-    glm::vec3 getZenithColor(float time) const;
-
     VkContext* vkCtx = nullptr;
 
     VkPipeline pipeline = VK_NULL_HANDLE;