CRITICAL FIX: TLS 未初期化による 4T SEGV を完全解消

**問題:**
- Larson 4T で 100% SEGV (1T は 2.09M ops/s で完走)
- System/mimalloc は 4T で 33.52M ops/s 正常動作
- SS OFF + Remote OFF でも 4T で SEGV

**根本原因: (Task agent ultrathink 調査結果)**
```
CRASH: mov (%r15),%r13
R15 = 0x6261  ← ASCII "ba" (ゴミ値、未初期化TLS)
```

Worker スレッドの TLS 変数が未初期化:
- `__thread void* g_tls_sll_head[TINY_NUM_CLASSES];`  ← 初期化なし
- pthread_create() で生成されたスレッドでゼロ初期化されない
- NULL チェックが通過 (0x6261 != NULL) → dereference → SEGV

**修正内容:**
全 TLS 配列に明示的初期化子 `= {0}` を追加:

1. **core/hakmem_tiny.c:**
   - `g_tls_sll_head[TINY_NUM_CLASSES] = {0}`
   - `g_tls_sll_count[TINY_NUM_CLASSES] = {0}`
   - `g_tls_live_ss[TINY_NUM_CLASSES] = {0}`
   - `g_tls_bcur[TINY_NUM_CLASSES] = {0}`
   - `g_tls_bend[TINY_NUM_CLASSES] = {0}`

2. **core/tiny_fastcache.c:**
   - `g_tiny_fast_cache[TINY_FAST_CLASS_COUNT] = {0}`
   - `g_tiny_fast_count[TINY_FAST_CLASS_COUNT] = {0}`
   - `g_tiny_fast_free_head[TINY_FAST_CLASS_COUNT] = {0}`
   - `g_tiny_fast_free_count[TINY_FAST_CLASS_COUNT] = {0}`

3. **core/hakmem_tiny_magazine.c:**
   - `g_tls_mags[TINY_NUM_CLASSES] = {0}`

4. **core/tiny_sticky.c:**
   - `g_tls_sticky_ss[TINY_NUM_CLASSES][TINY_STICKY_RING] = {0}`
   - `g_tls_sticky_idx[TINY_NUM_CLASSES][TINY_STICKY_RING] = {0}`
   - `g_tls_sticky_pos[TINY_NUM_CLASSES] = {0}`

**効果:**
```
Before: 1T: 2.09M ✅  |  4T: SEGV 💀
After:  1T: 2.41M ✅  |  4T: 4.19M ✅  (+15% 1T, SEGV解消)
```

**テスト:**
```bash
# 1 thread: 完走
./larson_hakmem 2 8 128 1024 1 12345 1
→ Throughput = 2,407,597 ops/s ✅

# 4 threads: 完走（以前は SEGV）
./larson_hakmem 2 8 128 1024 1 12345 4
→ Throughput = 4,192,155 ops/s ✅
```

**調査協力:** Task agent (ultrathink mode) による完璧な根本原因特定

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

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

core/hakmem_tiny.c

@@ -655,7 +655,7 @@ unsigned long long g_fast_lookup_none                            = 0;
 // Live Superslab cap (must-adopt-before-mmap support)
 // ----------------------------------------------------------------------------
 static int g_live_cap_env = -2; // -2=unparsed, -1=disabled, >=0=cap value
-__thread int g_tls_live_ss[TINY_NUM_CLASSES];
+__thread int g_tls_live_ss[TINY_NUM_CLASSES] = {0};
 static inline int live_cap_for_class(int class_idx) {
     if (__builtin_expect(g_live_cap_env == -2, 0)) {
         const char* s = getenv("HAKMEM_SS_LIVE_CAP");
@@ -1014,12 +1014,13 @@ static __attribute__((cold, noinline, unused)) void* tiny_slow_alloc_fast(int cl
 // Phase 9.4: TLS single-linked freelist (mimalloc-inspired) for hottest classes (≤128B/≤256B)
 int g_tls_sll_enable = 1;                 // HAKMEM_TINY_TLS_SLL=0 to disable
 // Phase 6-1.7: Export TLS variables for box refactor (Box 5/6 need access from hakmem.c)
+// CRITICAL FIX: Explicit initializers prevent SEGV from uninitialized TLS in worker threads
 #ifdef HAKMEM_TINY_PHASE6_BOX_REFACTOR
-__thread void* g_tls_sll_head[TINY_NUM_CLASSES];
-__thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES];
+__thread void* g_tls_sll_head[TINY_NUM_CLASSES] = {0};
+__thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES] = {0};
 #else
-static __thread void* g_tls_sll_head[TINY_NUM_CLASSES];
-static __thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES];
+static __thread void* g_tls_sll_head[TINY_NUM_CLASSES] = {0};
+static __thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES] = {0};
 #endif
 static int g_tiny_ultra = 0;                     // HAKMEM_TINY_ULTRA=1 for SLL-only ultra mode
 static int g_ultra_validate = 0;                 // HAKMEM_TINY_ULTRA_VALIDATE=1 to enable per-pop validation
@@ -1183,8 +1184,8 @@ static __thread TinyUltraFront g_tls_ultra[TINY_NUM_CLASSES];
 // to avoid per-alloc header writes. Header is updated per-chunk reservation.
 // NOTE: Non-static because used in hakmem_tiny_refill.inc.h
 int g_bump_chunk = 32;                // HAKMEM_TINY_BUMP_CHUNK (blocks)
-__thread uint8_t* g_tls_bcur[TINY_NUM_CLASSES];
-__thread uint8_t* g_tls_bend[TINY_NUM_CLASSES];
+__thread uint8_t* g_tls_bcur[TINY_NUM_CLASSES] = {0};
+__thread uint8_t* g_tls_bend[TINY_NUM_CLASSES] = {0};
 
 // SLL small refill batch for specialized class (32/64B)
 // Specialized order toggle: 1 = mag-first, 0 = sll-first