test(corpus): Java oracle — FILIUS 2.14 reads the corpus itself

tools/java-oracle builds FILIUS at 6640354 and loads every .fls through
its own private loader under Xvfb. All 23 files load with every node
positioned and every cable resolved (Swift: 20 of 25 nodes in the
Internet example). MAC addresses FILIUS generates are left out, so two
runs are byte-identical.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/java-oracle/run.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+# Reads every .fls under corpus/ with Java FILIUS itself and writes
+# corpus/corpus.java.json. Java is the arbiter for the file format (plan §13, M2).
+# Needs a JDK (17+), Maven and xvfb-run: FILIUS opens its main window while
+# loading (Information.reset → JMainFrame), so it needs a display, not headless.
+set -eu
+here="$(cd "$(dirname "$0")" && pwd)"
+root="$(cd "$here/../.." && pwd)"
+commit=6640354
+upstream="$here/.upstream"
+if [ ! -d "$upstream/.git" ]; then
+    git clone -q https://gitlab.com/filius1/filius.git "$upstream"
+fi
+if [ "$(git -C "$upstream" rev-parse --short=7 HEAD)" != "$commit" ]; then
+    git -C "$upstream" fetch -q origin
+    git -C "$upstream" checkout -q "$commit"
+    rm -rf "$upstream/target"
+fi
+if [ ! -f "$upstream/target/filius.jar" ]; then
+    (cd "$upstream" && mvn -q -DskipTests package dependency:copy-dependencies -DoutputDirectory=target/lib)
+fi
+classpath="$upstream/target/filius.jar:$upstream/target/lib/*"
+mkdir -p "$here/.build"
+javac -d "$here/.build" -cp "$classpath" "$here/src/FlsOracle.java"
+# FILIUS writes its settings below $HOME; keep them out of the real one.
+mkdir -p "$here/.build/home"
+# Removed first: a crashed run must not leave the previous result standing.
+rm -f "$root/corpus/corpus.java.json"
+HOME="$here/.build/home" xvfb-run -a java -cp "$classpath:$here/.build" FlsOracle \
+    "$root/corpus" "$root/corpus/corpus.java.json" 2>&1 | grep -v 'logback\|^$' || true
+test -s "$root/corpus/corpus.java.json"