fix: fix examples to use working patterns

- behavioral.lux: use verifiable behavioral patterns (abs for idempotent)
- behavioral_types.lux: use simpler verified patterns, proper main invocation
- schema_evolution.lux: simplify to runtime schema ops, fix record access
- jit_test.lux: add proper main function with console output

All examples now parse and run correctly.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

examples/jit_test.lux

@@ -9,8 +9,12 @@ fn factorial(n: Int): Int =
     if n <= 1 then 1
     else n * factorial(n - 1)
 
-fn main(): Int = {
-    let a = fib(30)
-    let b = factorial(10)
-    a + b
+fn main(): Unit with {Console} = {
+    let fibResult = fib(30)
+    let factResult = factorial(10)
+    Console.print("fib(30) = " + toString(fibResult))
+    Console.print("factorial(10) = " + toString(factResult))
+    Console.print("Total = " + toString(fibResult + factResult))
 }
+
+let output = run main() with {}