Micropub's replaceEntries() stores single-value arrays as plain strings
(JF2 normalization). Spreading a string into [...str] gives individual
characters, so hasSyndicationUrl() never matches existing syndication URLs
and alreadySyndicated is always false — causing re-syndication on every
webhook trigger.
Fix: use [].concat() which safely handles both string and array values.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
