Facade: split subsystem into one class per file, sync post code blocks to Java 25, add README mapping

02-structural/facade/VideoFile.java

@@ -0,0 +1,23 @@
+package facade;
+
+/**
+ * Complex subsystem classes — these are what the Facade hides.
+ * Each class has its own complex API; clients shouldn't need to know all of them.
+ */
+class VideoFile {
+    private final String filename;
+    private final String codecType;
+
+    VideoFile(String filename) {
+        this(filename, filename.endsWith(".mp4") ? "mpeg4" : "ogg");
+    }
+
+    VideoFile(String filename, String codec) {
+        this.filename  = filename;
+        this.codecType = codec;
+        System.out.println("  VideoFile: " + filename + " [codec: " + codecType + "]");
+    }
+
+    public String getFilename()  { return filename; }
+    public String getCodecType() { return codecType; }
+}