Base: BD-J Adjustments Blu-ray scaffold

Vendored BD-J SDK, tsMuxeR + local VLC plugins, ffmpeg asset generation,
and a signed BD-J Xlet menu (org.homebrew.MyXlet) authored into a UDF 2.50 ISO.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vendor/bdj-sdk/resources/AVCHD/BDMV/AUXDATA/dvb.fontindex

@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<!DOCTYPE fontdirectory PUBLIC "-//DVB//DTD Font Directory 1.0//EN"
+"http://www.dvb.org/mhp/dtd/fontdirectory-1-0.dtd">
+<fontdirectory>
+  <font>
+    <name>RobotoMono</name>
+    <fontformat>OTF</fontformat>
+    <filename>00000.otf</filename>
+    <style>PLAIN</style>
+  </font>
+  <font>
+    <name>Arial</name>
+    <fontformat>OTF</fontformat>
+    <filename>00001.otf</filename>
+    <style>BOLD</style>
+  </font>
+  <font>
+    <name>NewsGothicStd</name>
+    <fontformat>OTF</fontformat>
+    <filename>00002.otf</filename>
+    <style>BOLD</style>
+  </font>
+</fontdirectory>