fix(syncedinstance): Prevent same-instance syncs and sanitize post update payloads; update tests and docs

changelog.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## 2025-10-11 - 2.2.1 - fix(syncedinstance)
+Prevent same-instance syncs and sanitize post update payloads; update tests and docs
+
+- SyncedInstance now validates and normalizes source and target base URLs (trailing slashes and case) and throws a clear error when attempting to sync an instance to itself to prevent circular syncs.
+- Post.update signature changed to accept Partial<IPost>. Update logic now builds a sanitized payload and removes read-only/computed fields (uuid, comment_id, url, excerpt, reading_time, created_at, primary_author, primary_tag, etc.) before calling the Admin API to avoid conflicts.
+- Added/updated integration tests (dates, syncedinstance validation) and adjusted tag tests to be resilient; README expanded with examples, usage notes, and multi-instance sync safety details.
+- Improved tag sync/update to preserve slug when updating tags on targets.
+
 ## 2025-10-10 - 2.2.0 - feat(apiclient)
 Add native Admin & Content API clients, JWT generator, and tag visibility features; remove external @tryghost deps and update docs