Add shell safety options (pipefail)

Added 'set -o pipefail' to ensure pipe failures are detected.

Not using -e (errexit) as the script is designed for graceful
degradation when optional tools (smartctl, ceph) are missing.
Many commands intentionally redirect stderr to /dev/null.

Not using -u (nounset) as the script uses ${var:-default}
patterns extensively for optional variables.

Fixes: #23

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

driveAtlas.sh

@@ -5,6 +5,12 @@
 # Maps physical drive bays to logical device names using PCI paths
 #==============================================================================
 
+# Shell safety options:
+# -o pipefail: Exit status of pipe is rightmost non-zero exit code
+# Note: Not using -e (errexit) to allow graceful degradation when tools fail
+# Note: Not using -u (nounset) as script uses ${var:-default} patterns
+set -o pipefail
+
 VERSION="1.1.0"
 
 #------------------------------------------------------------------------------