change repair_tool application and add beams for salvager and repair_tool

src/lib/ecs/component/RepairToolComponent.h

@@ -6,7 +6,9 @@
 
 struct RepairToolComponent
 {
-    float ratePerTick;
+    float repairAmountHp;         // HP restored per repair cycle
+    int   repairIntervalTicks;    // cycle period = kTickRateHz / repair-rate (cycles/s); 0 = never
+    int   cooldownTicksRemaining; // ticks until this tool may start its next cycle
     float range_tiles;
     std::optional<entt::entity> currentTarget;
 };