make ships orbit their targets

src/lib/ecs/component/AttackBehavior.h

@@ -9,5 +9,6 @@
 struct AttackBehavior
 {
     std::optional<entt::entity> currentTarget;
+    float                       orbitRadius_tiles = 0.0f;  // REQ-SHP-ORBIT
     float                       score = 0.0f;
 };

src/lib/ecs/component/RallyBehavior.h

@@ -7,5 +7,6 @@
 struct RallyBehavior
 {
     QVector2D rallyPoint;
+    float     orbitRadius_tiles = 0.0f;  // REQ-SHP-ORBIT
     float     score = 0.0f;
 };

src/lib/ecs/component/RepairBehavior.h

@@ -11,5 +11,6 @@ struct RepairBehavior
 {
     std::optional<entt::entity> currentTarget;
     float                       maxRepairRange_tiles = 0.0f;
+    float                       orbitRadius_tiles = 0.0f;  // REQ-SHP-ORBIT
     float                       score = 0.0f;
 };

src/lib/ecs/component/SalvageScrapBehavior.h

@@ -10,5 +10,6 @@ struct SalvageScrapBehavior
 {
     std::optional<QVector2D> scrapTarget;
     float                    maxCollectionRange_tiles = 0.0f;
+    float                    orbitRadius_tiles = 0.0f;  // REQ-SHP-ORBIT
     float                    score = 0.0f;
 };