feat(memhub): [DET] 越界写打印块内容前16字节 - 定位 size=7 块被越界写的写入者（扫描 includes 阶段，后标记被写 0x0000）

includes/memhub.vp

@@ -883,8 +883,14 @@ class MemBuddy(MemManager):
             m16: t.CUInt16T | t.CPtr = (t.CUInt16T | t.CPtr)(t.CVoid(p + s, t.CPtr))
             mv: t.CUInt16T = m16[0]
             if mv != t.CUInt16T(MEMBUDDY_DET_MARKER):
-                stdio.printf("[DET] 越界写: ptr=%llu size=%llu 后标记=0x%04X（期望 0xCDCD）\n",
+                stdio.printf("[DET] 越界写: ptr=%llu size=%llu 后标记=0x%04X（期望 0xCDCD）块内容前16B: ",
                              p, s, t.CUInt32T(mv))
+                bi3: t.CInt = 0
+                while bi3 < 16:
+                    bv3: t.CUInt8T = (t.CUInt8T | t.CPtr)(t.CVoid(p + t.CUInt64T(bi3), t.CPtr))[0]
+                    stdio.printf("%02X ", t.CUInt32T(bv3))
+                    bi3 += 1
+                stdio.printf("\n")
                 stdlib.exit(1)
             i += 1