fix: Address multiple issues in debug script, array rendering, and custom feeds

1. debug_install.sh: Make log path dynamic instead of hardcoded
   - Compute project root from script location
   - Use dynamic LOG_DIR instead of hardcoded /home/ledpi/LEDMatrix/logs/
   - Works from any clone location and user

2. plugins_manager.js renderArrayObjectItem: Fix XSS and metadata issues
   - HTML-escape logoValue.path in img src attribute (XSS prevention)
   - Add data-file-data attribute to preserve file metadata for serialization
   - Add data-prop-key attribute for proper property tracking
   - Use schema-driven remove button label (x-removeLabel) with fallback to 'Remove item'

3. base.html addCustomFeedRow: Fix duplicate enabled field and hardcoded pluginId
   - Remove duplicate hidden input for enabled field (checkbox alone is sufficient)
   - Add pluginId parameter to function signature
   - Pass pluginId to handleCustomFeedLogoUpload instead of hardcoded 'ledmatrix-news'
   - Update caller in plugin_config.html to pass plugin_id

These fixes improve security (XSS prevention), functionality (metadata
preservation), and maintainability (no hardcoded values).

web_interface/templates/v3/partials/plugin_config.html

@@ -274,7 +274,7 @@
                                 </tbody>
                             </table>
                             <button type="button" 
-                                    onclick="addCustomFeedRow('{{ field_id }}', '{{ full_key }}', {{ max_items }})"
+                                    onclick="addCustomFeedRow('{{ field_id }}', '{{ full_key }}', {{ max_items }}, '{{ plugin_id }}')"
                                     class="mt-3 px-4 py-2 text-sm bg-blue-600 hover:bg-blue-700 text-white rounded-md"
                                     {% if array_value|length >= max_items %}disabled style="opacity: 0.5;"{% endif %}>
                                 <i class="fas fa-plus mr-1"></i> Add Feed