fix: correctly check mega-evme binary in command existence check

[Ocheretovich]

Handle cases where MEGA_EVME includes arguments by checking only the binary name. Prevents false negatives in command existence check

[Troublor]

The existence check fix is correct here — extracting the binary name via ${MEGA_EVME%% *} handles the case where MEGA_EVME contains arguments.

However, the actual invocation on line 101 still uses "$MEGA_EVME" (double-quoted), which means if MEGA_EVME="mega-evme --some-flag", bash will try to execute the entire string as a single command name rather than splitting it into command + arguments. So the scenario this PR fixes for the existence check would still fail at runtime.

To make this work end-to-end, line 101 should use $MEGA_EVME unquoted (to allow word splitting) or use an array-based approach:

Suggested change

	if ! command -v "$MEGA_EVME_BIN" &>/dev/null; then
	if ! command -v "$MEGA_EVME_BIN" &>/dev/null; then

And then also change line 101 from "$MEGA_EVME" to $MEGA_EVME (unquoted) so that arguments are properly word-split.