ENV Cleanup Step 17: Gate HAKMEM_TINY_RF_TRACE

Gate the refill trace debug variable behind #if !HAKMEM_BUILD_RELEASE:
- HAKMEM_TINY_RF_TRACE: Controls refill/mailbox publish path tracing
- File: core/tiny_publish.c:21-34 (1 call site gated)

Other 2 call sites already gated:
- core/tiny_refill.h:94 (already inside #if !HAKMEM_BUILD_RELEASE)
- core/box/mailbox_box.c:64 (already inside #if !HAKMEM_BUILD_RELEASE)

Performance: 30.7M ops/s avg (baseline maintained, 3 runs: 30.6M, 30.9M, 30.7M)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

core/tiny_publish.c

@@ -18,6 +18,7 @@ void tiny_publish_notify(int class_idx, SuperSlab* ss, int slab_idx) {
     g_pub_notify_calls[class_idx]++;
     tiny_debug_ring_record(TINY_RING_EVENT_SUPERSLAB_PUBLISH, (uint16_t)class_idx, ss, (uintptr_t)slab_idx);
     // One-shot visibility trace (env: HAKMEM_TINY_RF_TRACE)
+#if !HAKMEM_BUILD_RELEASE
     static int trace_en = -1;
     if (__builtin_expect(trace_en == -1, 0)) {
         const char* e = getenv("HAKMEM_TINY_RF_TRACE");
@@ -30,5 +31,6 @@ void tiny_publish_notify(int class_idx, SuperSlab* ss, int slab_idx) {
             fprintf(stderr, "[PUBTRACE] notify class=%d ss=%p slab=%d\n", class_idx, (void*)ss, slab_idx);
         }
     }
+#endif
     mailbox_box_publish(class_idx, ss, slab_idx);
 }