feat(vd960DBN): BLE 读取脱机日志 — OFFLOG_STAT/QUERY/CLEAR (0x25/0x26/0x27)

蓝牙通道补齐脱机日志读取 (此前仅 MQTT V1.06 / TCP JSON V1.02 有 log_* 命令):
- 3 条 BLE 命令, 语义对齐 MQTT log_stat/log_query/log_clear
- QUERY 直接传 32B OfflogEvt 原始结构 (二进制协议, 无需 JSON), 复用
  idx = start_seq - seq_first 定位, 不新增 offlog API
- 缓冲扩容: MAX_BLE_TMP_BUF_LEN 100→132, 新增 MAX_BLE_DAT_BUF_LEN=132
  (QUERY 响应 1+4x32B=129B), clear_buf_dbn_ble_all memset 同步
- 新协议文档 docs/DLD960_BLE协议.md V1.00 (帧格式+分包+命令+记录结构)
- 隔离测试 test_ble_offlog.c 嵌入源文件 3 case 真实文本, 7 例全过;
  offlog 回归 8 例 ALL PASS
- devlog V4.0; README 协议矩阵补 BLE 行

vd960DBN/tests/extract_offlog_cases.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+"""从 dbn_ble_srv.c 提取脱机日志 3 case 文本, 供 test_ble_offlog.c 隔离验证。
+
+用法: python3 extract_offlog_cases.py
+输出: ./offlog_cases_embedded.c (在 tests/ 目录下运行)
+
+原理: 测的是源文件真实代码而非拷贝 — 提取 `case CMD_DBN_OFFLOG_STAT`
+到 `default:` 之间的文本 (含 STAT/QUERY/CLEAR 3 case), 嵌入测试框架编译。
+"""
+import os
+
+SRC = os.path.join(os.path.dirname(__file__),
+                   "../BLE/OnlyUpdateApp_Peripheral/APP/dbn_ble_srv.c")
+OUT = os.path.join(os.path.dirname(__file__), "offlog_cases_embedded.c")
+
+with open(SRC, "rb") as f:
+    content = f.read()
+text = content.decode("utf-8", errors="replace").replace("\r\n", "\n")
+
+start = text.find("case CMD_DBN_OFFLOG_STAT")
+end = text.find("default:\n", start)
+if start == -1 or end == -1:
+    raise SystemExit("ERROR: 未找到 offlog 3 case (确认 dbn_ble_srv.c 已修改)")
+
+cases = text[start:end]
+for c in ("CMD_DBN_OFFLOG_STAT", "CMD_DBN_OFFLOG_QUERY", "CMD_DBN_OFFLOG_CLEAR"):
+    if c not in cases:
+        raise SystemExit(f"ERROR: 提取内容缺少 {c}")
+
+with open(OUT, "w") as f:
+    f.write(cases)
+print(f"OK: {OUT} ({len(cases)} bytes, 3 cases)")