ci: add shellcheck lint workflow; fix 5 violations

Adds shellcheck disable comments for intentional word-splitting on
\$COMMON_PKGS package list (SC2086). Adds -r flag to read (SC2162).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

freshStart.sh

@@ -52,12 +52,15 @@ COMMON_PKGS="python3-pip smartmontools python3-psutil python3-requests lm-sensor
 
 if [[ "$PLATFORM" == "pve" ]]; then
     echo "Installing PVE-specific packages..."
+    # shellcheck disable=SC2086  # intentional word splitting for package list
     apt-get install -y $COMMON_PKGS iperf3 fio nvme-cli
 elif [[ "$PLATFORM" == "pbs" ]]; then
     echo "Installing PBS-specific packages..."
+    # shellcheck disable=SC2086  # intentional word splitting for package list
     apt-get install -y $COMMON_PKGS zfsutils-linux nvme-cli
 else
     echo "Installing common packages..."
+    # shellcheck disable=SC2086  # intentional word splitting for package list
     apt-get install -y $COMMON_PKGS nvme-cli
 fi
 
@@ -320,7 +323,7 @@ else
     echo "You can enter it now or configure it later by editing:"
     echo "  /etc/hwmonDaemon/.env"
     echo ""
-    read -p "Enter API key (or press Enter to skip): " API_KEY
+    read -rp "Enter API key (or press Enter to skip): " API_KEY
 fi
 
 # Determine platform-specific defaults