wip(0.S1, 0.S2): state records, mut and read-only state parameters, entry injection, module var refused; ludic migrate state

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

examples/rejected/state_readonly.ludic

@@ -0,0 +1,11 @@
+# 0.S: a state taken without `mut` is read-only - assigning through it is refused
+program StateReadonly {
+  state Tally { n: int = 0 }
+  function peek(c: Tally) -> int {
+    c.n = 1
+    return c.n
+  }
+  entry (c: Tally) {
+    print(peek(c))
+  }
+}