fix: harden shell scripts with error handling and null guards

- dashboard.sh: Add // [] jq null guard on .data.array.disks[] (L176-177)
  Resolves review thread PRRT_kwDOO6Hdxs5uvO21

- dashboard.sh: Default NAME to server key when env var unset (L221)
  Resolves review thread PRRT_kwDOO6Hdxs5uvO22

- unraid-query.sh: Check curl exit code, empty response, and JSON validity
  before piping to jq (L112-129)
  Resolves review thread PRRT_kwDOO6Hdxs5uvO24

- disk-health.sh: Guard against missing query script and invalid responses
  Resolves review thread PRRT_kwDOO6Hdxs5uvKrh

skills/unraid/examples/disk-health.sh

@@ -5,12 +5,25 @@
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 QUERY_SCRIPT="$SCRIPT_DIR/../scripts/unraid-query.sh"
 
+if [[ ! -x "$QUERY_SCRIPT" ]]; then
+    echo "Error: Query script not found or not executable: $QUERY_SCRIPT" >&2
+    exit 1
+fi
+
 QUERY='{ array { disks { name device temp status isSpinning } } }'
 
 echo "=== Disk Health Report ==="
 echo ""
 
-RESPONSE=$("$QUERY_SCRIPT" -q "$QUERY" -f raw)
+RESPONSE=$("$QUERY_SCRIPT" -q "$QUERY" -f raw) || {
+    echo "Error: Query failed." >&2
+    exit 1
+}
+
+if [[ -z "$RESPONSE" ]] || ! echo "$RESPONSE" | jq -e . > /dev/null 2>&1; then
+    echo "Error: Invalid or empty response from query." >&2
+    exit 1
+fi
 
 echo "$RESPONSE" | jq -r '.array.disks[] | "\(.name) (\(.device)): \(.temp)°C - \(.status) - \(if .isSpinning then "Spinning" else "Spun down" end)"'
 

skills/unraid/scripts/dashboard.sh

@@ -173,8 +173,8 @@ process_server() {
     echo "" >> "$OUTPUT_FILE"
     echo "### Health" >> "$OUTPUT_FILE"
     
-    HOT_DISKS=$(echo "$RESPONSE" | jq -r '.data.array.disks[] | select(.temp > 45) | "- ⚠️  \(.name): \(.temp)°C (HIGH)"')
+    HOT_DISKS=$(echo "$RESPONSE" | jq -r '(.data.array.disks // [])[] | select(.temp > 45) | "- ⚠️  \(.name): \(.temp)°C (HIGH)"')
-    DISK_ERRORS=$(echo "$RESPONSE" | jq -r '.data.array.disks[] | select(.numErrors > 0) | "- ❌ \(.name): \(.numErrors) errors"')
+    DISK_ERRORS=$(echo "$RESPONSE" | jq -r '(.data.array.disks // [])[] | select(.numErrors > 0) | "- ❌ \(.name): \(.numErrors) errors"')
     
     if [ -z "$HOT_DISKS" ] && [ -z "$DISK_ERRORS" ]; then
         echo "- ✅ All disks healthy" >> "$OUTPUT_FILE"
@@ -218,7 +218,7 @@ for server in "${SERVERS[@]}"; do
     url_var="UNRAID_${server}_URL"
     key_var="UNRAID_${server}_API_KEY"
 
-    NAME="${!name_var}"
+    NAME="${!name_var:-$server}"
     URL="${!url_var}"
     KEY="${!key_var}"
 

skills/unraid/scripts/unraid-query.sh

@@ -112,7 +112,21 @@ CURL_FLAGS=("-sL" "-X" "POST")
 RESPONSE=$(curl "${CURL_FLAGS[@]}" "$URL" \
     -H "Content-Type: application/json" \
     -H "x-api-key: $API_KEY" \
-    -d "$PAYLOAD")
+    -d "$PAYLOAD") || {
+    echo "Error: curl request failed (exit code $?). Check URL and network connectivity." >&2
+    exit 1
+}
+
+if [[ -z "$RESPONSE" ]]; then
+    echo "Error: Empty response from server." >&2
+    exit 1
+fi
+
+if ! echo "$RESPONSE" | jq -e . > /dev/null 2>&1; then
+    echo "Error: Server returned invalid JSON. Response:" >&2
+    echo "$RESPONSE" | head -c 500 >&2
+    exit 1
+fi
 
 # Check for errors
 if echo "$RESPONSE" | jq -e '.errors' > /dev/null 2>&1; then