perf(chain): 禁用空块生产，防止磁盘快速耗尽

问题: skip_timeout_commit=true 导致 ~44ms/块，无交易时
空块以 ~23块/秒 速度堆积，约 2-3 GB/天纯空块数据。

修复: create_empty_blocks = false
- 没有待处理交易时不出块
- 有交易提交时立即触发出块，延迟不受影响
- 彻底消除空块造成的磁盘浪费

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blockchain/init-genesis.sh

@@ -111,6 +111,14 @@ sed -i 's/timeout_commit = "5s"/timeout_commit = "1s"/' "$CONFIG_TOML"
 # 实际出块时间可降到 500ms-800ms
 sed -i 's/skip_timeout_commit = false/skip_timeout_commit = true/' "$CONFIG_TOML"
 
+# ============================================================
+# 空块控制 — 防止磁盘快速耗尽
+# ============================================================
+# create_empty_blocks = false: 没有待处理交易时不出空块
+# 有交易提交时立即触发出块，延迟不受影响
+# 避免 ~23块/秒 的空块堆积 (按44ms/块计算 ≈ 2-3 GB/天)
+sed -i 's/create_empty_blocks = true/create_empty_blocks = false/' "$CONFIG_TOML"
+
 # ============================================================
 # Mempool 优化 — 提升交易吞吐
 # ============================================================
@@ -136,4 +144,5 @@ echo "  - Consensus timeouts:   prevote/precommit 500ms (reduced from 1s)"
 echo "  - IAVL cache:           2,000,000 nodes (up from 781,250)"
 echo "  - Mempool size:         10,000 txs (up from 5,000)"
 echo "  - Mempool cache:        20,000 (up from 10,000)"
+echo "  - Empty blocks:         DISABLED (only produce blocks when txs pending)"
 echo "============================================================"