# Email Logo Display Fix

## Problem
Email logos were not displaying correctly. Gmail was proxying images through `ci3.googleusercontent.com`, showing broken URLs like:
```
https://ci3.googleusercontent.com/meips/...#http://logoapi.sportcreative.eu/logos/7eacd9f0-bfa0-4928-a9b6-936140168f58?format=svg
```

## Root Causes
1. **SVG format incompatibility**: SVG images are not well-supported in email clients
2. **Email client proxying**: Gmail and other email clients proxy external images, which can fail for certain formats
3. **Poor fallback**: Used non-existent placeholder URL

## Solution Implemented

### Changes in `pkg/email/service.go`
Updated all email functions to use PNG format instead of SVG:

**Before:**
```go
clubLogo = fmt.Sprintf("https://logoapi.sportcreative.eu/logos/%s?format=svg", clubID)
```

**After:**
```go
// Use PNG format for better email client compatibility (SVG not widely supported)
clubLogo = fmt.Sprintf("https://logoapi.sportcreative.eu/logos/%s?format=png&width=400", clubID)
```

### Affected Functions
1. ✅ `SendAdminWelcome()` - Line 86
2. ✅ `SendPasswordResetCode()` - Line 237
3. ✅ `SendPasswordReset()` - Line 345
4. ✅ `SendEmail()` - Line 644
5. ✅ `SendNewsletter()` - Line 899

### Improved Fallback
Changed from:
```go
clubLogo = "https://your-club-logo.png"  // Non-existent URL
```

To:
```go
clubLogo = "https://via.placeholder.com/400x400.png?text=Logo"  // Working placeholder
```

## Benefits
- ✅ **Better compatibility**: PNG format works in all email clients
- ✅ **Proper sizing**: Added `width=400` parameter for optimal display
- ✅ **Reliable fallback**: Using a working placeholder service
- ✅ **Gmail proxy friendly**: PNG images pass through email proxies without issues

## Testing Recommendations
1. Send a test newsletter to verify logo displays correctly
2. Test on multiple email clients (Gmail, Outlook, Apple Mail)
3. Verify the logoapi service responds correctly with PNG format
4. Check that fallback placeholder works if ClubID is not set

## Alternative Solutions (Future Consideration)
1. **Host logos locally**: Upload logos to your own server/CDN for full control
2. **Use base64 encoding**: Embed small logos directly in email HTML
3. **Multiple format fallback**: Include both PNG and JPG variants
