Fix RemoveTrailingWhitespace to preserve shebang lines

rewrite-java/src/main/java/org/openrewrite/java/format/RemoveTrailingWhitespaceVisitor.java

@@ -57,7 +57,8 @@ public Space visitSpace(Space space, Space.Location loc, P p) {
         String whitespace = s.getWhitespace();
         int lastNewline = whitespace.lastIndexOf('\n');
         // Skip import prefixes, leave those up to OrderImports which better understands that domain
-        if (lastNewline > 0 && loc != Space.Location.IMPORT_PREFIX) {
+        // Skip compilation unit prefix to preserve shebangs and other file-level prefixes
+        if (lastNewline > 0 && loc != Space.Location.IMPORT_PREFIX && loc != Space.Location.COMPILATION_UNIT_PREFIX) {
             StringBuilder ws = new StringBuilder();
             for (int i = 0; i < whitespace.length(); i++) {
                 char c = whitespace.charAt(i);

rewrite-javascript/src/integTest/java/org/openrewrite/javascript/RemoveTrailingWhitespaceTest.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.javascript;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.openrewrite.Issue;
+import org.openrewrite.java.format.RemoveTrailingWhitespace;
+import org.openrewrite.javascript.rpc.JavaScriptRewriteRpc;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+import org.openrewrite.test.TypeValidation;
+
+import static org.openrewrite.javascript.Assertions.javascript;
+
+class RemoveTrailingWhitespaceTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new RemoveTrailingWhitespace());
+    }
+
+    @AfterEach
+    void after() {
+        JavaScriptRewriteRpc.shutdownCurrent();
+    }
+
+    @Issue("https://github.com/openrewrite/rewrite/issues/6274")
+    @Test
+    void doNotRemoveShebang() {
+        rewriteRun(
+          javascript(
+            """
+              #!/usr/bin/env node
+
+              /**
+              * Generate llms.txt and llms-full.txt for OpenRewrite documentation
+              */
+              """
+          )
+        );
+    }
+}