[SECURITY] Missing length validation for CFE_EVS_SEND_HK_MID in EVS ProcessCommandPacket

Describe the bug
CFE_EVS_ProcessCommandPacket() processes SEND_HK_MID messages by directly casting the buffer to CFE_EVS_SendHkCmd_t * without calling CFE_EVS_VerifyCmdLength(). All other command codes in CFE_EVS_ProcessGroundCommand() use VerifyCmdLength before casting. A malformed/truncated packet can cause OOB read when EVS accesses the struct fields.

This is the same root cause as #971 (TIME DATA_CMD_MID missing length validation) and #986 (ES SEND_HK_MID missing length validation).

To Reproduce

1. Send a CFE_EVS_SEND_HK_MID packet with size < sizeof(CFE_EVS_SendHkCmd_t)
2. EVS processes it without validation
3. OOB read when fields are accessed

Expected behavior
CFE_EVS_ProcessCommandPacket() should call CFE_EVS_VerifyCmdLength(&SBBufPtr->Msg, sizeof(CFE_EVS_SendHkCmd_t)) before casting.

Code snips
File: cfe/modules/evs/fsw/src/cfe_evs_dispatch.c, function CFE_EVS_ProcessCommandPacket():

if (CFE_SB_MsgId_Equal(MessageID, SEND_HK_MID))
{
    CFE_EVS_SendHkCmd((const CFE_EVS_SendHkCmd_t *)SBBufPtr); // بدون VerifyCmdLength!
}

Reporter Info
Erfan, Independent Space Software Security Researcher

Start in cfe/modules/evs/fsw/src/cfe_evs_dispatch.c at CFE_EVS_ProcessCommandPacket(), and compare the SEND_HK_MID branch with the other command-code branches that call CFE_EVS_VerifyCmdLength(). The work is complete when truncated CFE_EVS_SEND_HK_MID packets are rejected before the command structure is accessed, without changing valid-packet handling.