feat: integrate lightning system for storm weather and heavy rain

The lightning system (lightning.hpp/cpp) was fully implemented but never
wired into the renderer. Connect it now:
- Enable lightning during server storm weather (wType==3, intensity>0.1)
  and heavy rain (wType==1, intensity>0.7) as a bonus visual
- Scale lightning intensity proportionally to weather intensity
- Render in both parallel (SEC_POST) and fallback rendering paths
- Update and shutdown alongside the weather system
- Show active lightning info in the performance HUD weather section

include/rendering/renderer.hpp

@@ -39,6 +39,7 @@ class StarField;
 class Clouds;
 class LensFlare;
 class Weather;
+class Lightning;
 class LightingManager;
 class SwimEffects;
 class MountDust;
@@ -127,6 +128,7 @@ public:
     Clouds* getClouds() const { return skySystem ? skySystem->getClouds() : nullptr; }
     LensFlare* getLensFlare() const { return skySystem ? skySystem->getLensFlare() : nullptr; }
     Weather* getWeather() const { return weather.get(); }
+    Lightning* getLightning() const { return lightning.get(); }
     CharacterRenderer* getCharacterRenderer() const { return characterRenderer.get(); }
     WMORenderer* getWMORenderer() const { return wmoRenderer.get(); }
     M2Renderer* getM2Renderer() const { return m2Renderer.get(); }
@@ -216,6 +218,7 @@ private:
     std::unique_ptr<Clouds> clouds;
     std::unique_ptr<LensFlare> lensFlare;
     std::unique_ptr<Weather> weather;
+    std::unique_ptr<Lightning> lightning;
     std::unique_ptr<LightingManager> lightingManager;
     std::unique_ptr<SkySystem> skySystem;  // Coordinator for sky rendering
     std::unique_ptr<SwimEffects> swimEffects;

src/rendering/performance_hud.cpp

@@ -10,6 +10,7 @@
 #include "rendering/clouds.hpp"
 #include "rendering/lens_flare.hpp"
 #include "rendering/weather.hpp"
+#include "rendering/lightning.hpp"
 #include "rendering/character_renderer.hpp"
 #include "rendering/wmo_renderer.hpp"
 #include "rendering/m2_renderer.hpp"
@@ -369,6 +370,11 @@ void PerformanceHUD::render(const Renderer* renderer, const Camera* camera) {
                 ImGui::Text("Intensity: %.0f%%", weather->getIntensity() * 100.0f);
             }
 
+            auto* lightning = renderer->getLightning();
+            if (lightning && lightning->isEnabled()) {
+                ImGui::Text("Lightning: active (%.0f%%)", lightning->getIntensity() * 100.0f);
+            }
+
             ImGui::Spacing();
         }
     }

src/rendering/renderer.cpp

@@ -12,6 +12,7 @@
 #include "rendering/clouds.hpp"
 #include "rendering/lens_flare.hpp"
 #include "rendering/weather.hpp"
+#include "rendering/lightning.hpp"
 #include "rendering/lighting_manager.hpp"
 #include "rendering/sky_system.hpp"
 #include "rendering/swim_effects.hpp"
@@ -699,6 +700,9 @@ bool Renderer::initialize(core::Window* win) {
     weather = std::make_unique<Weather>();
     weather->initialize(vkCtx, perFrameSetLayout);
 
+    lightning = std::make_unique<Lightning>();
+    lightning->initialize(vkCtx, perFrameSetLayout);
+
     swimEffects = std::make_unique<SwimEffects>();
     swimEffects->initialize(vkCtx, perFrameSetLayout);
 
@@ -802,6 +806,11 @@ void Renderer::shutdown() {
         weather.reset();
     }
 
+    if (lightning) {
+        lightning->shutdown();
+        lightning.reset();
+    }
+
     if (swimEffects) {
         swimEffects->shutdown();
         swimEffects.reset();
@@ -942,6 +951,7 @@ void Renderer::applyMsaaChange() {
     if (characterRenderer) characterRenderer->recreatePipelines();
     if (questMarkerRenderer) questMarkerRenderer->recreatePipelines();
     if (weather) weather->recreatePipelines();
+    if (lightning) lightning->recreatePipelines();
     if (swimEffects) swimEffects->recreatePipelines();
     if (mountDust) mountDust->recreatePipelines();
     if (chargeEffect) chargeEffect->recreatePipelines();
@@ -2863,6 +2873,20 @@ void Renderer::update(float deltaTime) {
                 weather->updateZoneWeather(currentZoneId, deltaTime);
             }
             weather->setEnabled(true);
+
+            // Enable lightning during storms (wType==3) and heavy rain
+            if (lightning) {
+                uint32_t wType2 = gh->getWeatherType();
+                float wInt2 = gh->getWeatherIntensity();
+                bool stormActive = (wType2 == 3 && wInt2 > 0.1f)
+                                || (wType2 == 1 && wInt2 > 0.7f);
+                lightning->setEnabled(stormActive);
+                if (stormActive) {
+                    // Scale intensity: storm at full, heavy rain proportionally
+                    float lIntensity = (wType2 == 3) ? wInt2 : (wInt2 - 0.7f) / 0.3f;
+                    lightning->setIntensity(lIntensity);
+                }
+            }
         } else if (weather) {
             // No game handler (single-player without network) — zone weather only
             weather->updateZoneWeather(currentZoneId, deltaTime);
@@ -2932,6 +2956,11 @@ void Renderer::update(float deltaTime) {
         weather->update(*camera, deltaTime);
     }
 
+    // Update lightning (storm / heavy rain)
+    if (lightning && camera && lightning->isEnabled()) {
+        lightning->update(deltaTime, *camera);
+    }
+
     // Update swim effects
     if (swimEffects && camera && cameraController && waterRenderer) {
         swimEffects->update(*camera, *cameraController, *waterRenderer, deltaTime);
@@ -5217,6 +5246,7 @@ void Renderer::renderWorld(game::World* world, game::GameHandler* gameHandler) {
             if (waterRenderer && camera)
                 waterRenderer->render(cmd, perFrameSet, *camera, globalTime, false, frameIdx);
             if (weather && camera) weather->render(cmd, perFrameSet);
+            if (lightning && camera && lightning->isEnabled()) lightning->render(cmd, perFrameSet);
             if (swimEffects && camera) swimEffects->render(cmd, perFrameSet);
             if (mountDust && camera) mountDust->render(cmd, perFrameSet);
             if (chargeEffect && camera) chargeEffect->render(cmd, perFrameSet);
@@ -5353,6 +5383,7 @@ void Renderer::renderWorld(game::World* world, game::GameHandler* gameHandler) {
         if (waterRenderer && camera)
             waterRenderer->render(currentCmd, perFrameSet, *camera, globalTime, false, frameIdx);
         if (weather && camera) weather->render(currentCmd, perFrameSet);
+        if (lightning && camera && lightning->isEnabled()) lightning->render(currentCmd, perFrameSet);
         if (swimEffects && camera) swimEffects->render(currentCmd, perFrameSet);
         if (mountDust && camera) mountDust->render(currentCmd, perFrameSet);
         if (chargeEffect && camera) chargeEffect->render(currentCmd, perFrameSet);