This PR fixes undefined behavior in direct-route path rewriting by replacing an overlapping memcpy with memmove.

Problem / Impact

removeSelfFromPath() shifts path entries left in-place after decrementing the hop count.
Source and destination ranges overlap by design (dest = path + k, src = path + k + sz).

Using memcpy on overlapping ranges is undefined behavior in C/C++.

On embedded builds, UB here can lead to:

• corrupted route paths,
• intermittent forwarding failures,
• architecture/libc/optimization-dependent behavior that is difficult to reproduce and debug.

Because this function is in the packet forwarding path, even rare corruption can have high network reliability impact.

Why This Fix Is Correct

memmove is defined for overlapping memory regions and preserves the intended in-place shift semantics.