refactor: simplify ChainResolver and RayCaster interfaces, enhance ChainDamageApplier logic

- Updated ChainResolver to remove unused shooterOrigin and shooterDirection parameters, streamlining the resolve method.
- Modified RayCaster interface to reflect changes in method signature, focusing on maxBlocks only.
- Enhanced ChainDamageApplier to utilize a new CauseIndexHolder for resolving the PHYSICAL damage cause index, improving clarity and performance.
- Refactored ChainDamageApplier.apply method to use HytaleEntityAdapter for target references, ensuring correct damage application.
- Adjusted tests in ChainResolverTest and ChainDamageApplierTest to align with the new method signatures and logic.

Tests: All tests passing. Build: ./gradlew clean build successful.

src/main/java/com/mythlane/chainlightning/chain/RayCaster.java

@@ -2,8 +2,8 @@ package com.mythlane.chainlightning.chain;
 
 import java.util.Optional;
 
-/** SAM that returns the first entity hit along a ray, or empty. */
+/** SAM that returns the first entity along the caster's look ray, or empty. */
 @FunctionalInterface
 public interface RayCaster {
-    Optional<ChainEntity> firstHit(Vec3 origin, Vec3 direction, double maxBlocks);
+    Optional<ChainEntity> firstHit(double maxBlocks);
 }