Fix test chemistry, remove 66 EBIMatrix locks, validate inputs, clean dead code

Test correctness:
- AldolCleavage: fix unbalanced SMILES (5C→4C, now 4C→4C balanced)
- RingOpeningOzonolysis: add missing water product (oxygen balance)
- AlanineRacemase: test stereo fingerprint instead of null check
- R00001: replace trivially-true assertion with assertNotNull

API robustness:
- ReactionMechanismTool: add null reaction validation (throws
  IllegalArgumentException); warn on empty reactants/products;
  replace synchronizedList with plain ArrayList
- EBIMatrix: remove synchronized from all 66 methods (not designed
  for concurrent access, lock overhead was pure waste)

Cleanup:
- TestUtility: remove ~250 lines of dead commented-out code
- Mark SMSDTest and UnblancedReactionChecker as manual utilities

All 46 tests pass. Net -251 lines.

Author: Syed Asad Rahman <asad.rahman@bioinceptionlabs.com>

Author: asad

src/main/java/com/bioinceptionlabs/reactionblast/mechanism/ReactionMechanismTool.java

@@ -59,7 +59,6 @@
 import static java.lang.Integer.parseInt;
 import static java.lang.Math.abs;
 import static java.lang.System.getProperty;
-import static java.util.Collections.synchronizedList;
 
 import org.openscience.cdk.smiles.SmiFlavor;
 import static org.openscience.cdk.tools.manipulator.AtomContainerManipulator.getAtomArray;
@@ -153,10 +152,17 @@ public ReactionMechanismTool(IReaction reaction,
             boolean checkComplex,
             boolean accept_no_change,
             IStandardizer standardizer) throws CDKException, AssertionError, Exception {
-        this.allSolutions = synchronizedList(new ArrayList<>());
+        if (reaction == null) {
+            throw new IllegalArgumentException("Reaction cannot be null");
+        }
+        this.allSolutions = new ArrayList<>();
         this.selectedMapping = null;
         this.accept_no_change = accept_no_change;//transporter reactions
 
+        if (reaction.getReactantCount() == 0 || reaction.getProductCount() == 0) {
+            LOGGER.warn("Reaction has no reactants or no products: {0}", reaction.getID());
+        }
+
         /*
          * IMP: Set all null hydrogen counts to 0, else CDKToBeam cries out loudly
          */