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/behavioral.lux

@@ -3,20 +3,14 @@
 //
 // Expected output:
 // add(5, 3) = 8
-// clamp(150, 0, 100) = 100
 // factorial(5) = 120
 // multiply(7, 6) = 42
+// abs(-5) = 5
 
 // A pure function - no side effects, same input always gives same output
 fn add(a: Int, b: Int): Int is pure =
     a + b
 
-// An idempotent function - applying twice gives same result as once
-fn clamp(value: Int, min: Int, max: Int): Int is idempotent =
-    if value < min then min
-    else if value > max then max
-    else value
-
 // A deterministic function - same input always gives same output
 fn factorial(n: Int): Int is deterministic =
     if n <= 1 then 1
@@ -26,18 +20,22 @@ fn factorial(n: Int): Int is deterministic =
 fn multiply(a: Int, b: Int): Int is commutative =
     a * b
 
+// An idempotent function - absolute value
+fn abs(x: Int): Int is idempotent =
+    if x < 0 then 0 - x else x
+
 // Test the functions
 let sumResult = add(5, 3)
-let clampedResult = clamp(150, 0, 100)
 let factResult = factorial(5)
 let productResult = multiply(7, 6)
+let absResult = abs(0 - 5)
 
 // Print results
 fn printResults(): Unit with {Console} = {
     Console.print("add(5, 3) = " + toString(sumResult))
-    Console.print("clamp(150, 0, 100) = " + toString(clampedResult))
     Console.print("factorial(5) = " + toString(factResult))
     Console.print("multiply(7, 6) = " + toString(productResult))
+    Console.print("abs(-5) = " + toString(absResult))
 }
 
 let output = run printResults() with {}