Phase 7-Step6: Fix include order issue - refill path optimization complete

**Problem**: Include order dependency prevented using TINY_FRONT_FASTCACHE_ENABLED
macro in hakmem_tiny_refill.inc.h (included before tiny_alloc_fast.inc.h).

**Solution** (from ChatGPT advice):
- Move wrapper functions to tiny_front_config_box.h as static inline
- This makes them available regardless of include order
- Enables dead code elimination in PGO mode for refill path

**Changes**:
1. core/box/tiny_front_config_box.h:
   - Add tiny_fastcache_enabled() and sfc_cascade_enabled() as static inline
   - These access static global variables via extern declaration

2. core/hakmem_tiny_refill.inc.h:
   - Include tiny_front_config_box.h
   - Use TINY_FRONT_FASTCACHE_ENABLED macro (line 162)
   - Enables dead code elimination in PGO mode

3. core/tiny_alloc_fast.inc.h:
   - Remove duplicate wrapper function definitions
   - Now uses functions from config box header

**Performance**: 79.8M ops/s (maintained, 77M/81M/81M across 3 runs)

**Design Principle**: Config Box as "single entry point" for Tiny Front policy
- All config checks go through TINY_FRONT_*_ENABLED macros
- Wrapper functions centralized in config box header
- Include order independent (static inline in header)

🐱 Generated with ChatGPT advice for solving include order dependencies

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

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

core/hakmem_tiny_refill.inc.h

@@ -19,6 +19,7 @@
 #include "superslab/superslab_inline.h"
 #include "box/tls_sll_box.h"
 #include "box/tiny_header_box.h"  // Header Box: Single Source of Truth for header operations
+#include "box/tiny_front_config_box.h"  // Phase 7-Step6-Fix: Config macros for dead code elimination
 #include "hakmem_tiny_integrity.h"
 #include "box/tiny_next_ptr_box.h"
 #include "tiny_region_id.h"   // For HEADER_MAGIC/HEADER_CLASS_MASK (prepare header before SLL push)
@@ -157,7 +158,8 @@ static inline void* superslab_tls_bump_fast(int class_idx) {
 
 static inline void* tiny_fast_refill_and_take(int class_idx, TinyTLSList* tls) {
     // 1) Front FastCache から直接
-    if (__builtin_expect(g_fastcache_enable && class_idx <= 3, 1)) {
+    // Phase 7-Step6-Fix: Use config macro for dead code elimination in PGO mode
+    if (__builtin_expect(TINY_FRONT_FASTCACHE_ENABLED && class_idx <= 3, 1)) {
         void* fc = fastcache_pop(class_idx);
         if (fc) {
             extern unsigned long long g_front_fc_hit[TINY_NUM_CLASSES];