feat(ai): add wander AI system with move boost

Add AIBase and WanderAITag components, a WanderAISystem, and a MoveBoost component to control wandering behavior. Replace the old MoveState with MoveBoost and include a horizontal random direction helper.

src/gameplay/systems/wander_ai_system.cpp

@@ -0,0 +1,40 @@
+#include "Cubed/gameplay/systems/wander_ai_system.hpp"
+
+#include "Cubed/gameplay/ecs/ai_struct.hpp"
+#include "Cubed/gameplay/ecs/server_entity.hpp"
+#include "Cubed/tools/cubed_random.hpp"
+
+namespace {
+constexpr double DIRECTION_PROBABILITY = 0.1;
+constexpr double MOVE_PROBABILITY = 0.1;
+} // namespace
+
+namespace Cubed {
+void WanderAISystem::update(entt::registry& registry) {
+    auto view =
+        registry.view<AIBase, WanderAITag, BaseServerCreature, MoveBoost>();
+
+    for (auto e : view) {
+        auto [ai, creature, move_boost] =
+            view.get<AIBase, BaseServerCreature, MoveBoost>(e);
+        ++ai.count;
+        if (ai.count >= ai.interval) {
+            ai.count = 0;
+            do_ai(creature, move_boost);
+        }
+    }
+}
+
+void WanderAISystem::do_ai(BaseServerCreature& creature,
+                           MoveBoost& move_boost) {
+    thread_local Random r{std::random_device()()};
+    if (r.random_bool(DIRECTION_PROBABILITY)) {
+        creature.direction.value = r.random_direction_horizontal();
+    }
+    if (r.random_bool(MOVE_PROBABILITY)) {
+        move_boost.duration = r.random_int(5, 8);
+        move_boost.count = 0;
+    }
+}
+
+} // namespace Cubed