Add installer functionality for WordPress with FTP and database configuration

- Create SQL migration for prompt templates used in article and image generation.
- Add migration to change publish interval from days to hours in the sites table.
- Implement InstallerController to handle installation requests and validation.
- Develop FtpService for FTP connections and file uploads.
- Create InstallerService to manage the WordPress installation process, including downloading, extracting, and configuring WordPress.
- Add index view for the installer with form inputs for FTP, database, and WordPress admin settings.
- Implement progress tracking for the installation process with AJAX polling.

src/Helpers/Validator.php

@@ -38,6 +38,14 @@ class Validator
         return $this;
     }
 
+    public function email(string $field, mixed $value, string $label = ''): self
+    {
+        if (!empty($value) && !filter_var($value, FILTER_VALIDATE_EMAIL)) {
+            $this->errors[$field] = ($label ?: $field) . ' musi być prawidłowym adresem e-mail.';
+        }
+        return $this;
+    }
+
     public function isValid(): bool
     {
         return empty($this->errors);