Remove legacy JVM-specific file system, shell, and related implementations; migrate to platform-agnostic and common main modules.

src/jvmMain/java/mtmc/lang/sea/ast/SyntaxError.java

@@ -0,0 +1,7 @@
+package mtmc.lang.sea.ast;
+
+import mtmc.lang.ParseException;
+
+public interface SyntaxError extends Error {
+    ParseException exception();
+}