[Copilot]

RSS <guid isPermaLink="false"> allows non-URL identifiers, but the library had no way to set or preserve this attribute — guids were always emitted without it, forcing values to be valid URLs.

Changes

• NodeInterface / Node: Added bool $isPermaLink = true parameter to setPublicId() and a getPublicIdIsPermaLink(): bool getter. The flag is stored as $publicIdIsPermaLink (defaults true, fully backwards-compatible).
• Rule/PublicId::setProperty(): Reads isPermaLink attribute from parsed DOM element ('false' → false, anything else → true) and forwards it to setPublicId(). Simplified the link-auto-set condition to use the resolved flag.
• Rule/PublicId::addElement(): Emits isPermaLink="false" on the <guid> element when the flag is false; omits the attribute otherwise (RSS default is true).

Usage

// Non-URL identifier, will render as <guid isPermaLink="false">urn:uuid:...</guid>
$item->setPublicId('urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a', false);

// Default behaviour unchanged — permalink assumed
$item->setPublicId('https://example.com/post/1');