Java 27 and 26: runnable demos and captured output for every JEP, plus version lanes

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01B38FGKKam5SCGgwgduVAh3

docs/output/94-release-flag.txt

@@ -0,0 +1,24 @@
+# ReleaseFlag.java calls String.equalsFoldCase, which is new in Java 26. The compiler is JDK 27's javac both times.
+
+$ javac --release 25 ReleaseFlag.java
+    <repo>/lanes/src/ReleaseFlag.java:8: error: cannot find symbol
+            System.out.println("ABC".equalsFoldCase("abc"));
+                                    ^
+      symbol:   method equalsFoldCase(String)
+      location: class String
+    1 error
+    exit=1
+
+$ javac -source 25 -target 25 ReleaseFlag.java
+    warning: [options] location of system modules is not set in conjunction with -source 25
+      not setting the location of system modules may lead to class files that cannot run on JDK 25
+        --release 25 is recommended instead of -source 25 -target 25 because it sets the location of system modules automatically
+    1 warning
+    exit=0
+
+$ java -cp rf-b ReleaseFlag      (JDK 25)
+    Exception in thread "main" java.lang.NoSuchMethodError: 'boolean java.lang.String.equalsFoldCase(java.lang.String)'
+    	at ReleaseFlag.main(ReleaseFlag.java:8)
+
+$ java -cp rf-b ReleaseFlag      (JDK 27)
+    true