[Copilot]

Feed-level links were modeled as a single setLink() value, making it impossible to represent both a homepage (rel="alternate") and a canonical feed URL (rel="self") — a requirement for valid Atom feeds.

New API

• FeedIo\Feed\Node\FeedLink — value object with rel, href, type
• Feed::addLink(string $rel, string $href, ?string $type) — appends to an explicit link collection
• Feed::getLinks(): iterable — iterates all explicit links
• Feed::setHomePageUrl(string $url) / getHomePageUrl() — convenience alias over setLink() + addLink('alternate', ..., 'text/html')
• Feed::setFeedUrl(string $url) / getFeedUrl() — convenience alias over setUrl() + addLink('self', ..., 'application/atom+xml')

Atom formatting

Rule\Atom\LinkNode::addElement() now emits per-link <link rel="..." href="..." type="..."/> elements when the feed has an explicit links collection. Falls back to the existing single <link href="..."/> behavior when none are present.

// New convenience API
$feed->setHomePageUrl('https://example.com/');
$feed->setFeedUrl('https://example.com/feed.atom');

// Or explicit control
$feed->addLink('alternate', 'https://example.com/', 'text/html');
$feed->addLink('self', 'https://example.com/feed.atom', 'application/atom+xml');

Atom output:

<link rel="alternate" href="https://example.com/" type="text/html"/>
<link rel="self" href="https://example.com/feed.atom" type="application/atom+xml"/>

Backward compatibility

setLink() behavior is unchanged. The multi-link path is only activated when addLink() (or the new convenience methods) are used.