Remove unused StringUtils.hashString and FastMath.hash

Neither matches the client string hash; Hasher.SBStringHash does.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/math/FastMath.java

@@ -583,36 +583,6 @@ final public class FastMath {
         return ret.normalize();
     }
 
-    /**
-     * Turns a String into an Integer hash that the client will recognize.
-     *
-     * @param s The String to hash
-     * @return the Integer hash
-     */
-    public static int hash(String s) {
-        int out = 0, pad = 0;
-        for (char c : s.toCharArray()) {
-            if (c == ' ' || c == '\\') {
-                pad += 5;
-                continue;
-            }
-            if (c > 0x40 && c < 0x60)
-                out ^= _rotl((byte) 0x60, pad);
-            out ^= _rotl((byte) (c & 0xDF), pad);
-            pad += 5;
-        }
-        return out;
-    }
-
-    /**
-     * Utility function for making hashes
-     */
-    private static int _rotl(int value, int shift) {
-        if ((shift &= 31) == 0)
-            return value;
-        return (value << shift) | (value >> (32 - shift));
-    }
-
     /**
      * Gets number of seconds until next hours
      */