Restore C7 Warm/TLS carve for release and add policy scaffolding

core/box/tiny_policy_learner_box.c

@@ -0,0 +1,7 @@
+// tiny_policy_learner_box.c - Placeholder learner hook
+
+#include "tiny_policy_learner_box.h"
+
+void tiny_policy_learner_tick(void) {
+    // FROZEN/OBSERVE: intentionally empty.
+}