diff --git a/.mokogitea/workflows/pr-check.yml b/.mokogitea/workflows/pr-check.yml
index 473eeb2..3dd7540 100644
--- a/.mokogitea/workflows/pr-check.yml
+++ b/.mokogitea/workflows/pr-check.yml
@@ -147,6 +147,98 @@ jobs:
           echo "PHP lint: ${ERRORS} error(s)"
           [ "$ERRORS" -eq 0 ] || { echo "::error::PHP syntax errors found"; exit 1; }
 
+      - name: Joomla JEXEC guard check
+        if: steps.platform.outputs.platform == 'joomla'
+        run: |
+          ERRORS=0
+          while IFS= read -r -d '' file; do
+            # Skip vendor, node_modules, and index.html stub files
+            case "$file" in ./vendor/*|./node_modules/*) continue ;; esac
+            # Check first 10 lines for JEXEC or JPATH guard
+            if ! head -20 "$file" | grep -qE "defined\s*\(\s*['\"](_JEXEC|JPATH_BASE|\\\\JPATH_PLATFORM)['\"]"; then
+              echo "::error file=${file}::Missing JEXEC guard: ${file}"
+              ERRORS=$((ERRORS + 1))
+            fi
+          done < <(find . -name "*.php" -path "*/src/*" -not -path "./.git/*" -not -path "./vendor/*" -print0)
+          if [ "$ERRORS" -gt 0 ]; then
+            echo "::error::${ERRORS} PHP file(s) missing defined('_JEXEC') or die guard"
+            echo "## JEXEC Guard Check: Failed" >> $GITHUB_STEP_SUMMARY
+            echo "${ERRORS} file(s) in src/ are missing the Joomla execution guard." >> $GITHUB_STEP_SUMMARY
+            exit 1
+          fi
+          echo "JEXEC guard: OK"
+
+      - name: Joomla directory listing protection
+        if: steps.platform.outputs.platform == 'joomla'
+        run: |
+          MISSING=0
+          SOURCE_DIR="src"
+          [ ! -d "$SOURCE_DIR" ] && exit 0
+          while IFS= read -r dir; do
+            if [ ! -f "${dir}/index.html" ]; then
+              echo "::warning::Missing index.html in ${dir} (directory listing protection)"
+              MISSING=$((MISSING + 1))
+            fi
+          done < <(find "$SOURCE_DIR" -type d -not -path "./.git/*" -not -path "*/vendor/*" -not -path "*/node_modules/*")
+          if [ "$MISSING" -gt 0 ]; then
+            echo "## Directory Protection" >> $GITHUB_STEP_SUMMARY
+            echo "${MISSING} director(ies) missing index.html" >> $GITHUB_STEP_SUMMARY
+          fi
+          echo "Directory protection: ${MISSING} missing (advisory)"
+
+      - name: Joomla script file and asset checks
+        if: steps.platform.outputs.platform == 'joomla'
+        run: |
+          ERRORS=0
+          MANIFEST=$(find . -maxdepth 3 -name "*.xml" ! -path "./.git/*" -exec grep -l '<extension' {} \; 2>/dev/null | head -1)
+          [ -z "$MANIFEST" ] && exit 0
+          MANIFEST_DIR=$(dirname "$MANIFEST")
+
+          # Check scriptfile exists if declared
+          SCRIPTFILE=$(sed -n 's/.*<scriptfile>\([^<]*\)<\/scriptfile>.*/\1/p' "$MANIFEST" 2>/dev/null)
+          if [ -n "$SCRIPTFILE" ]; then
+            if [ ! -f "${MANIFEST_DIR}/${SCRIPTFILE}" ]; then
+              echo "::error::Manifest declares <scriptfile>${SCRIPTFILE}</scriptfile> but file not found at ${MANIFEST_DIR}/${SCRIPTFILE}"
+              ERRORS=$((ERRORS + 1))
+            else
+              echo "Script file: ${MANIFEST_DIR}/${SCRIPTFILE} (OK)"
+            fi
+          fi
+
+          # Require joomla.asset.json and validate it
+          ASSET_JSON=$(find "$MANIFEST_DIR" -name "joomla.asset.json" -not -path "./.git/*" 2>/dev/null | head -1)
+          if [ -z "$ASSET_JSON" ]; then
+            echo "::error::joomla.asset.json not found — Joomla asset system is required"
+            ERRORS=$((ERRORS + 1))
+          else
+            if command -v php &> /dev/null; then
+              php -r "json_decode(file_get_contents('$ASSET_JSON')); if(json_last_error()!==JSON_ERROR_NONE){echo json_last_error_msg();exit(1);}" 2>&1 || {
+                echo "::error::joomla.asset.json is not valid JSON"
+                ERRORS=$((ERRORS + 1))
+              }
+            fi
+            echo "joomla.asset.json: valid"
+          fi
+
+          # Validate all XML files in src/ are well-formed
+          XML_ERRORS=0
+          if command -v php &> /dev/null; then
+            while IFS= read -r -d '' xmlfile; do
+              if ! php -r "libxml_use_internal_errors(true); \$x = simplexml_load_file('$xmlfile'); if(!\$x){foreach(libxml_get_errors() as \$e) echo trim(\$e->message) . ' in $xmlfile'; exit(1);}" 2>&1; then
+                XML_ERRORS=$((XML_ERRORS + 1))
+              fi
+            done < <(find "$MANIFEST_DIR" -name "*.xml" -not -path "./.git/*" -print0)
+          fi
+          if [ "$XML_ERRORS" -gt 0 ]; then
+            echo "::error::${XML_ERRORS} XML file(s) are malformed"
+            ERRORS=$((ERRORS + 1))
+          else
+            echo "XML well-formedness: OK"
+          fi
+
+          [ "$ERRORS" -gt 0 ] && exit 1
+          echo "Joomla asset checks: OK"
+
       - name: Validate platform manifest
         run: |
           PLATFORM="${{ steps.platform.outputs.platform }}"