Add WoW-style camera system with collision and first-person mode

- Implement orbit camera with smooth zoom and collision detection
- Add 50° slope limiting with sliding (prevents mountain climbing)
- Add first-person mode that hides player model and weapons
- Add floor clearance check to prevent camera clipping through ground
- Improve WMO wall collision with proper height range checks
- Add two-sided floor collision detection for WMO geometry
- Increase M2 render distance slightly for better visibility

src/rendering/character_renderer.cpp

@@ -978,6 +978,10 @@ void CharacterRenderer::render(const Camera& camera, const glm::mat4& view, cons
 
     for (const auto& pair : instances) {
         const auto& instance = pair.second;
+
+        // Skip invisible instances (e.g., player in first-person mode)
+        if (!instance.visible) continue;
+
         const auto& gpuModel = models[instance.modelId];
 
         // Set model matrix (use override for weapon instances)
@@ -1118,6 +1122,21 @@ void CharacterRenderer::setActiveGeosets(uint32_t instanceId, const std::unorder
     }
 }
 
+void CharacterRenderer::setInstanceVisible(uint32_t instanceId, bool visible) {
+    auto it = instances.find(instanceId);
+    if (it != instances.end()) {
+        it->second.visible = visible;
+
+        // Also hide/show attached weapons (for first-person mode)
+        for (const auto& wa : it->second.weaponAttachments) {
+            auto weapIt = instances.find(wa.weaponInstanceId);
+            if (weapIt != instances.end()) {
+                weapIt->second.visible = visible;
+            }
+        }
+    }
+}
+
 void CharacterRenderer::removeInstance(uint32_t instanceId) {
     instances.erase(instanceId);
 }