feat: extend snapshots to include custom fields and tags (#57)

When articles are included in a snapshot, now also captures:
- #__tags (tag definitions)
- #__fields (custom field definitions for com_content.article)
- #__fields_values (custom field values)
- #__fields_categories (field-to-category mappings)

Restore correctly scopes deletes to avoid touching non-content fields.

Closes #57

source/packages/com_mokosuitebackup/src/Engine/SnapshotEngine.php

@@ -41,6 +41,10 @@ class SnapshotEngine
 	private const ARTICLE_RELATED = [
 		'#__workflow_associations',
 		'#__contentitem_tag_map',
+		'#__tags',
+		'#__fields',
+		'#__fields_values',
+		'#__fields_categories',
 	];
 
 	/**
@@ -107,6 +111,32 @@ class SnapshotEngine
 				$rows = $this->dumpTagMap($db, $prefix);
 				$data['tables']['#__contentitem_tag_map'] = $rows;
 				$this->log('  #__contentitem_tag_map: ' . count($rows) . ' rows');
+
+				// Tags — dump all (shared, small table)
+				$rows = $this->dumpTable($db, str_replace('#__', $prefix, '#__tags'), '#__tags', 'articles');
+				$data['tables']['#__tags'] = $rows;
+				$this->log('  #__tags: ' . count($rows) . ' rows');
+
+				// Custom fields — only com_content.article context
+				$rows = $this->dumpFilteredTable(
+					$db,
+					str_replace('#__', $prefix, '#__fields'),
+					'#__fields',
+					'context',
+					'com_content.article'
+				);
+				$data['tables']['#__fields'] = $rows;
+				$this->log('  #__fields: ' . count($rows) . ' rows');
+
+				// Field values — dump all (small, article-scoped)
+				$rows = $this->dumpTable($db, str_replace('#__', $prefix, '#__fields_values'), '#__fields_values', 'articles');
+				$data['tables']['#__fields_values'] = $rows;
+				$this->log('  #__fields_values: ' . count($rows) . ' rows');
+
+				// Field-category mappings — only for com_content.article fields
+				$rows = $this->dumpFieldCategories($db, $prefix);
+				$data['tables']['#__fields_categories'] = $rows;
+				$this->log('  #__fields_categories: ' . count($rows) . ' rows');
 			}
 
 			// Count items
@@ -231,6 +261,30 @@ class SnapshotEngine
 		return $db->loadAssocList() ?: [];
 	}
 
+	/**
+	 * Dump field-category mappings for com_content.article fields.
+	 *
+	 * Uses a subquery: field_id IN (SELECT id FROM #__fields WHERE context = 'com_content.article')
+	 */
+	private function dumpFieldCategories(object $db, string $prefix): array
+	{
+		$fcTable = $prefix . 'fields_categories';
+		$fTable  = $prefix . 'fields';
+
+		$subQuery = $db->getQuery(true)
+			->select($db->quoteName('id'))
+			->from($db->quoteName($fTable))
+			->where($db->quoteName('context') . ' = ' . $db->quote('com_content.article'));
+
+		$query = $db->getQuery(true)
+			->select('*')
+			->from($db->quoteName($fcTable))
+			->where($db->quoteName('field_id') . ' IN (' . $subQuery . ')');
+		$db->setQuery($query);
+
+		return $db->loadAssocList() ?: [];
+	}
+
 	private function log(string $message): void
 	{
 		$this->log[] = '[' . date('H:i:s') . '] ' . $message;

source/packages/com_mokosuitebackup/src/Engine/SnapshotRestoreEngine.php

@@ -33,6 +33,10 @@ class SnapshotRestoreEngine
 		'#__contentitem_tag_map'     => null,  // composite key, handled specially
 		'#__modules'                 => 'id',
 		'#__modules_menu'            => null,  // composite key, handled specially
+		'#__tags'                    => 'id',
+		'#__fields'                  => 'id',
+		'#__fields_values'           => null,  // composite key, handled specially
+		'#__fields_categories'       => null,  // composite key, handled specially
 	];
 
 	/**
@@ -282,6 +286,40 @@ class SnapshotRestoreEngine
 				$query->where($db->quoteName('moduleid') . ' IN (' . implode(',', $moduleIds) . ')');
 				break;
 
+			case '#__tags':
+				// Only delete tags that exist in the snapshot — never wipe all tags
+				$ids = array_filter(array_column($rows, 'id'));
+
+				if (empty($ids)) {
+					return;
+				}
+
+				$ids = array_map('intval', $ids);
+				$query->where($db->quoteName('id') . ' IN (' . implode(',', $ids) . ')');
+				break;
+
+			case '#__fields':
+				// Only delete custom fields scoped to com_content.article
+				$query->where($db->quoteName('context') . ' = ' . $db->quote('com_content.article'));
+				break;
+
+			case '#__fields_values':
+				// Delete all field values — they are article-scoped
+				break;
+
+			case '#__fields_categories':
+				// Delete field-category mappings for com_content.article fields only
+				$prefix = $db->getPrefix();
+				$fTable = $prefix . 'fields';
+
+				$subQuery = $db->getQuery(true)
+					->select($db->quoteName('id'))
+					->from($db->quoteName($fTable))
+					->where($db->quoteName('context') . ' = ' . $db->quote('com_content.article'));
+
+				$query->where($db->quoteName('field_id') . ' IN (' . $subQuery . ')');
+				break;
+
 			// #__content and #__content_frontpage are fully owned by com_content
 			default:
 				break;
@@ -303,6 +341,10 @@ class SnapshotRestoreEngine
 			$tables[] = '#__content_frontpage';
 			$tables[] = '#__workflow_associations';
 			$tables[] = '#__contentitem_tag_map';
+			$tables[] = '#__tags';
+			$tables[] = '#__fields';
+			$tables[] = '#__fields_values';
+			$tables[] = '#__fields_categories';
 		}
 
 		if (in_array('categories', $types)) {