chore(release): bump version to v4.1.5

Ships Modbus gateway support (multiple slave IDs behind a single IP) and two
compilation hardening fixes: run_compile now fails closed so a crash never
strands status at COMPILING, and the parallel build caps -j by total RAM as
well as nproc to avoid OOM-deadlock on small Pis.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: thiagoralves

VERSION

@@ -1 +1 @@
-v4.1.4
+v4.1.5