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>

benchmarks/scripts/run_vm_mixed_matrix.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Run VM-mixed (512KB–<2MB) bench across allocators and L25 A/B, save CSV.
+# Usage: benchmarks/scripts/run_vm_mixed_matrix.sh [cycles] [ws] [reps]
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")"/../.. && pwd)"
+cd "$ROOT_DIR"
+
+cycles=${1:-20000}
+ws=${2:-256}
+reps=${3:-5}
+
+outdir="bench_results/auto/vm_mixed_$(date +%Y%m%d_%H%M%S)"
+mkdir -p "$outdir"
+csv="$outdir/results.csv"
+echo "ts,scenario,allocator,env,cycles,ws,rep,throughput_ops_s" >"$csv"
+
+run_case() {
+  local scenario="$1"; shift
+  local alloc="$1"; shift
+  local envstr="$1"; shift
+  local bin="$1"; shift
+  for ((i=1;i<=reps;i++)); do
+    local ts=$(date +%H%M%S)
+    local out
+    out=$($envstr "$bin" "$cycles" "$ws" 4242 2>/dev/null || true)
+    local tput=$(echo "$out" | awk '/Throughput =/{print $3; exit}')
+    if [[ -n "${tput:-}" ]]; then
+      echo "$ts,$scenario,$alloc,$(echo "$envstr" | sed 's/,/;/g'),$cycles,$ws,$i,$tput" >>"$csv"
+    fi
+  done
+}
+
+# Build benches if needed
+[[ -x ./bench_vm_mixed_system ]] || make -s bench_vm_mixed_system >/dev/null
+[[ -x ./bench_vm_mixed_hakmem ]] || make -s bench_vm_mixed_hakmem >/dev/null
+
+echo "[info] writing CSV to $csv"
+
+# system
+run_case "vm_mixed" "system" "env -i" ./bench_vm_mixed_system
+
+# HAKMEM L25 OFF/ON
+run_case "vm_mixed" "hakmem(l25=0)" "env -i HAKMEM_BIGCACHE_L25=0 HAKMEM_WRAP_TINY=1" ./bench_vm_mixed_hakmem
+run_case "vm_mixed" "hakmem(l25=1)" "env -i HAKMEM_BIGCACHE_L25=1 HAKMEM_WRAP_TINY=1" ./bench_vm_mixed_hakmem
+
+echo "[done] $csv"