feat: Card-based email system implementation
## ✅ Core Card System Complete!
### base.html Template
- ✅ Single, theme-agnostic template
- ✅ Card system CSS (default, highlight, info, warning, success, bg)
- ✅ Customizable header (logo/text)
- ✅ Customizable footer + social icons
- ✅ Customizable body background
- ✅ Mobile responsive
- ✅ Email client compatible (Outlook, Gmail, etc.)
### EmailRenderer.php - Card Parser
- ✅ `parse_cards()` - Parses [card]...[/card] syntax
- ✅ `parse_card_attributes()` - Extracts type and bg attributes
- ✅ `render_card()` - Renders card HTML
- ✅ `render_card_spacing()` - 24px spacing between cards
- ✅ `render_html()` - Email customization support
- ✅ `get_social_icon_url()` - Social media icons
### Card Types Supported
```
[card] → Default white card
[card type="highlight"] → Purple gradient card
[card type="info"] → Blue info card
[card type="warning"] → Yellow warning card
[card type="success"] → Green success card
[card bg="https://..."] → Background image card
```
### Email Customization
- ✅ Header: Logo or text
- ✅ Body background color
- ✅ Footer text
- ✅ Social media links (Facebook, Instagram, Twitter, LinkedIn)
- ✅ Stored in `woonoow_notification_settings[email_appearance]`
### Default Templates Updated
- ✅ order_placed_email - Multi-card layout
- ✅ order_processing_email - Success card + summary
- ✅ Other templates ready to update
---
**Architecture:**
```
Content with [card] tags
↓
parse_cards()
↓
render_card() × N
↓
base.html template
↓
Beautiful HTML email! 🎨
```
**Next:** Settings UI + Live Preview 🚀
1573bff7b3