Improve SQLite db copying with file_exists guards

Co-authored-by: swissspidy <841956+swissspidy@users.noreply.github.com>

Author: Copilot

src/Context/FeatureContext.php

@@ -1614,7 +1614,10 @@ public function install_wp( $subdir = '', $version = '' ): void {
 
 		$install_cache_path = self::$install_cache_dir . '/install_' . md5( implode( ':', $install_args ) . ':subdir=' . $subdir );
 
-		if ( file_exists( $install_cache_path ) ) {
+		$install_cache_is_valid = file_exists( $install_cache_path )
+			&& ( 'sqlite' !== self::$db_type || file_exists( "{$install_cache_path}.sqlite" ) );
+
+		if ( $install_cache_is_valid ) {
 			self::copy_dir( $install_cache_path, $run_dir );
 
 			// This is the sqlite equivalent of restoring a database dump in MySQL
@@ -1627,7 +1630,9 @@ public function install_wp( $subdir = '', $version = '' ): void {
 		} else {
 			$this->proc( 'wp core install', $install_args, $subdir )->run_check();
 
-			mkdir( $install_cache_path );
+			if ( ! is_dir( $install_cache_path ) ) {
+				mkdir( $install_cache_path );
+			}
 
 			self::dir_diff_copy( $run_dir, self::$cache_dir, $install_cache_path );
 
@@ -1646,7 +1651,10 @@ public function install_wp( $subdir = '', $version = '' ): void {
 
 			if ( 'sqlite' === self::$db_type ) {
 				// This is the sqlite equivalent of creating a database dump in MySQL
-				copy( "$run_dir/wp-content/database/.ht.sqlite", "{$install_cache_path}.sqlite" );
+				$sqlite_source = "$run_dir/wp-content/database/.ht.sqlite";
+				if ( file_exists( $sqlite_source ) ) {
+					copy( $sqlite_source, "{$install_cache_path}.sqlite" );
+				}
 			}
 		}
 	}