⚡ Bolt: Replace expensive FindObjectsOfType with Rack cache

[mleem97]

💡 What:
Replaces the expensive UnityEngine.Object.FindObjectsOfType<Rack>() call across the codebase with an O(1) thread-safe static cache in RackPatch. The cache tracks active Racks by hooking into their Awake and OnDestroy lifecycle methods via Harmony.

🎯 Why:
FindObjectsOfType is an O(N) operation that traverses every active GameObject in the scene. In late-game saves with thousands of objects, frequent API or Lua polling of Rack counts or data causes significant main thread hitches and severe Garbage Collection pressure due to array allocation.

📊 Impact:

• Reduces GC allocations to 0 bytes for count queries.
• Turns O(N) scene traversal into O(1) cached lookup.
• Prevents main-thread stutter when API/Lua scripts query Rack info frequently.

🔬 Measurement:

• Use a Unity profiler or MelonLogger stopwatch around GregAPI.GetRackCount() or greg.rack.count(). You will see time drop from several milliseconds (in large saves) to negligible nanoseconds.
• Build compiles and tests succeed (dotnet build gregCore.csproj -c Release).

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PR created automatically by Jules for task 292053595981774687 started by @mleem97

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