fix(vcr): prevent vcr-data modification in PLAYBACK mode

Fixes three bugs that caused vcr-data files to be modified even when
tests were configured with @VCRTest(mode = VCRMode.PLAYBACK):

1. Fixed @nested test class annotation lookup - The VCRExtension was not
   finding @VCRTest annotations on enclosing classes for nested tests,
   causing it to fall back to the default PLAYBACK_OR_RECORD mode.
   Added findVCRTestAnnotation() to walk up the class hierarchy.

2. Added temp directory copy for playback mode - In PLAYBACK mode, the
   vcr-data directory is now copied to a temp directory before mounting
   to Docker, preventing any modifications to the source files.

3. Fixed registry writes in playback mode - testSuccessful() and
   testFailed() now check the mode before writing to the registry,
   only updating it when recording.

Additional changes:
- Disabled Redis AOF persistence in playback mode (--appendonly no)
- Disabled Redis RDB saves in playback mode (--save "")

Author: bsbodden

core/src/main/java/com/redis/vl/test/vcr/VCRContext.java

@@ -1,8 +1,13 @@
 package com.redis.vl.test.vcr;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.StandardCopyOption;
+import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -132,10 +137,22 @@ public VCRCassetteStore getCassetteStore() {
   private void startRedis() {
     String redisCommand = buildRedisCommand();
 
+    // In playback mode, copy data to temp directory to prevent modifications to source files
+    Path mountPath = dataDir;
+    if (!effectiveMode.isRecordMode()) {
+      try {
+        mountPath = copyDataToTemp();
+      } catch (Exception e) {
+        System.err.println(
+            "VCR: Failed to copy data to temp directory, using original: " + e.getMessage());
+        mountPath = dataDir;
+      }
+    }
+
     redisContainer =
         new GenericContainer<>(DockerImageName.parse(config.redisImage()))
             .withExposedPorts(6379)
-            .withFileSystemBind(dataDir.toAbsolutePath().toString(), "/data", BindMode.READ_WRITE)
+            .withFileSystemBind(mountPath.toAbsolutePath().toString(), "/data", BindMode.READ_WRITE)
             .withCommand(redisCommand);
 
     redisContainer.start();
@@ -150,22 +167,59 @@ private void startRedis() {
 
   private String buildRedisCommand() {
     StringBuilder cmd = new StringBuilder("redis-stack-server");
-    cmd.append(" --appendonly yes");
-    cmd.append(" --appendfsync everysec");
     cmd.append(" --dir /data");
     cmd.append(" --dbfilename dump.rdb");
 
     if (effectiveMode.isRecordMode()) {
-      // Enable periodic saves in record mode
+      // Enable AOF and periodic saves in record mode
+      cmd.append(" --appendonly yes");
+      cmd.append(" --appendfsync everysec");
       cmd.append(" --save 60 1 --save 300 10");
     } else {
-      // Disable saves in playback mode for speed
+      // Disable all persistence in playback mode (read-only)
+      cmd.append(" --appendonly no");
       cmd.append(" --save \"\"");
     }
 
     return cmd.toString();
   }
 
+  /**
+   * Copies VCR data to a temporary directory to prevent modifications to source files. Used in
+   * playback mode to ensure cassette files are not modified.
+   *
+   * @return path to the temporary directory containing the copied data
+   * @throws IOException if copying fails
+   */
+  private Path copyDataToTemp() throws IOException {
+    Path tempDir = Files.createTempDirectory("vcr-playback-");
+    tempDir.toFile().deleteOnExit();
+
+    Files.walkFileTree(
+        dataDir,
+        new SimpleFileVisitor<>() {
+          @Override
+          public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs)
+              throws IOException {
+            Path targetDir = tempDir.resolve(dataDir.relativize(dir));
+            Files.createDirectories(targetDir);
+            return FileVisitResult.CONTINUE;
+          }
+
+          @Override
+          public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
+              throws IOException {
+            Path targetFile = tempDir.resolve(dataDir.relativize(file));
+            Files.copy(file, targetFile, StandardCopyOption.REPLACE_EXISTING);
+            return FileVisitResult.CONTINUE;
+          }
+        });
+
+    System.out.println(
+        "VCR: Using temporary copy at " + tempDir + " for playback (read-only protection)");
+    return tempDir;
+  }
+
   private void waitForRedis() {
     for (int i = 0; i < 30; i++) {
       try {

core/src/main/java/com/redis/vl/test/vcr/VCRExtension.java

@@ -70,7 +70,8 @@ public class VCRExtension
   @Override
   public void beforeAll(ExtensionContext extensionContext) throws Exception {
     // Get VCR configuration from @VCRTest annotation
-    VCRTest config = extensionContext.getRequiredTestClass().getAnnotation(VCRTest.class);
+    // Walk up the class hierarchy to find the annotation (handles @Nested test classes)
+    VCRTest config = findVCRTestAnnotation(extensionContext.getRequiredTestClass());
 
     if (config == null) {
       // No @VCRTest annotation, use defaults
@@ -208,8 +209,11 @@ public void testSuccessful(ExtensionContext extensionContext) {
       return;
     }
 
-    String testId = getTestId(extensionContext);
-    context.getRegistry().registerSuccess(testId, context.getCurrentCassetteKeys());
+    // Only update registry when recording, not in playback mode
+    if (context.getEffectiveMode().isRecordMode()) {
+      String testId = getTestId(extensionContext);
+      context.getRegistry().registerSuccess(testId, context.getCurrentCassetteKeys());
+    }
   }
 
   @Override
@@ -218,11 +222,12 @@ public void testFailed(ExtensionContext extensionContext, Throwable cause) {
       return;
     }
 
-    String testId = getTestId(extensionContext);
-    context.getRegistry().registerFailure(testId, cause.getMessage());
+    // Only update registry and delete cassettes when recording
+    if (context.getEffectiveMode().isRecordMode()) {
+      String testId = getTestId(extensionContext);
+      context.getRegistry().registerFailure(testId, cause.getMessage());
 
-    // Optionally delete cassettes for failed tests in RECORD mode
-    if (context.getEffectiveMode() == VCRMode.RECORD) {
+      // Delete cassettes for failed tests in RECORD mode
       context.deleteCassettes(context.getCurrentCassetteKeys());
     }
   }
@@ -251,6 +256,29 @@ private String getTestId(ExtensionContext ctx) {
     return ctx.getRequiredTestClass().getName() + ":" + ctx.getRequiredTestMethod().getName();
   }
 
+  /**
+   * Finds the @VCRTest annotation on the given class or any of its enclosing classes. This is
+   * needed to properly handle @Nested test classes where the annotation is on the outer class.
+   *
+   * @param testClass the test class to search
+   * @return the VCRTest annotation if found, null otherwise
+   */
+  private VCRTest findVCRTestAnnotation(Class<?> testClass) {
+    Class<?> currentClass = testClass;
+
+    // Walk up the class hierarchy (enclosing classes for nested classes)
+    while (currentClass != null) {
+      VCRTest annotation = currentClass.getAnnotation(VCRTest.class);
+      if (annotation != null) {
+        return annotation;
+      }
+      // Check enclosing class for @Nested test classes
+      currentClass = currentClass.getEnclosingClass();
+    }
+
+    return null;
+  }
+
   /** Default VCRTest annotation values for when no annotation is present. */
   @VCRTest
   private static class DefaultVCRTest {