**Issue:** Core had default allowed meta fields for specific addons
- OrdersController: _tracking_number, _tracking_provider, etc.
- ProductsController: _custom_field
**Problem:** This violates our core principle:
❌ WooNooW Core = Zero addon dependencies
❌ We do NOT support specific plugins in core
❌ We do NOT hardcode addon fields
**Solution:** Empty defaults, plugins register via filters
**Before:**
```php
$allowed = apply_filters('woonoow/order_allowed_private_meta', [
'_tracking_number', // ❌ Addon-specific
'_tracking_provider', // ❌ Addon-specific
], $order);
```
**After:**
```php
// Core has ZERO defaults - plugins register via filter
$allowed = apply_filters('woonoow/order_allowed_private_meta', [], $order);
```
**How Plugins Register:**
```php
// Shipment Tracking plugin (or any plugin)
add_filter('woonoow/order_allowed_private_meta', function($allowed) {
$allowed[] = '_tracking_number';
$allowed[] = '_tracking_provider';
return $allowed;
});
```
**Principle Maintained:**
✅ Core has ZERO addon dependencies
✅ Core does NOT know about specific plugins
✅ Plugins register themselves via standard WP filters
✅ Community does the integration, not core
**Changed:**
- OrdersController: Empty defaults for allowed/updatable meta
- ProductsController: Empty defaults for allowed/updatable meta
- Added comments: 'Core has ZERO defaults - plugins register via filter'
**Result:**
- Public meta (no underscore): Always exposed automatically
- Private meta (starts with _): Only if plugin registers via filter
- Clean separation: Core provides mechanism, plugins use it
9f731bfe0a