Implement WoW 3.3.5a DBC-driven lighting system

Add complete Blizzard-style time-of-day lighting pipeline:

Spatial Volume System (Light.dbc):
- Light volumes with position + inner/outer radius
- Distance-based weighting with smoothstep falloff
- Multi-volume blending (top 2 with normalized weights)
- X,Z,Y coordinate handling + LIGHT_COORD_SCALE for ×36 quirk
- Smooth zone transitions without popping

Profile Selection (LightParams.dbc):
- Weather variants: clear/rain/underwater
- Links to 18 color + 6 float band curves per profile
- Block indexing: LightParamsID × 18/6 + channel

Time-of-Day Band Sampling (LightIntBand/LightFloatBand):
- Half-minutes format (0-2879) with time clamping
- Keyframe interpolation with midnight wrap
- Wrap-safe initialization for edge cases
- BGR color unpacking

Multi-Volume Blending:
- Weighted sum of all lighting params
- Proper direction blending: normalize(sum(dir × weight))
- Blends ambient, diffuse, fog, sky, cloud density

Temporal Smoothing:
- Exponential blend to prevent frame snapping
- Smooths ALL parameters (colors, fog, direction, sky)

Game Time Support:
- Accepts server-sent game time (WoW standard)
- Falls back to local time if not provided
- Manual override for testing

Debug Features:
- Volume distance/weight logging
- Fog params logging
- Coordinate scale verification

Also: Move buff bar to top-left under player frame

src/ui/game_screen.cpp

@@ -3010,15 +3010,14 @@ void GameScreen::renderBuffBar(game::GameHandler& gameHandler) {
     }
     if (activeCount == 0) return;
 
-    auto* window = core::Application::getInstance().getWindow();
-    float screenW = window ? static_cast<float>(window->getWidth()) : 1280.0f;
     auto* assetMgr = core::Application::getInstance().getAssetManager();
 
-    // Position below the minimap (minimap is 200px + 10px margin from top-right)
+    // Position below the player frame in top-left
     constexpr float ICON_SIZE = 32.0f;
     constexpr int ICONS_PER_ROW = 8;
     float barW = ICONS_PER_ROW * (ICON_SIZE + 4.0f) + 8.0f;
-    ImGui::SetNextWindowPos(ImVec2(screenW - barW - 10.0f, 220.0f), ImGuiCond_Always);
+    // Dock under player frame in top-left (player frame is at 10, 30 with ~110px height)
+    ImGui::SetNextWindowPos(ImVec2(10.0f, 145.0f), ImGuiCond_Always);
     ImGui::SetNextWindowSize(ImVec2(barW, 0), ImGuiCond_Always);
 
     ImGuiWindowFlags flags = ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove |