kyte-php v4.8.1

Fix: republish is now fault-isolated (KYTE-#181) + partial content saves no longer blank block_layout (KYTE-#189)

Republish resilience (KYTE-#181). ApplicationController's republish_kyte_connect hook re-stamps every state=1 page across all of an app's sites. Previously it throwew on the first page with missing KytePageData, aborting the entire batch — every later site/page kept the stale connect string, leaving an app half-migrated (e.g. a JWT dashboard with an HMAC login page). Now each page is re-stamped inside a try/catch: failures are collected (page id, s3key, site, reason) and logged, and the loop continues. The result is surfaced on the response as republish_summary (succeeded / failed / failures[]) so the caller can show a real outcome instead of trusting a silent all-or-nothing hook. Also fixed: CloudFront invalidation ran once outside the sites loop, so only the last site was invalidated — it now runs per site, so multi-site apps no longer leave other sites' caches stale.

block_layout preservation (KYTE-#189). The KytePage update content-save unconditionally wrote block_layout, blanking it to empty when the field wasn't in the payload. A partial save — notably the Shipyard IDE, which sends only html/stylesheet/javascript — would therefore wipe an existing block-editor layout. The update now only overwrites block_layout when it's actually provided, preserving the stored value otherwise. (The IDE "save silently doesn't persist" half of #189 was already resolved by the v4.8.0 guard relaxation; this closes the data-loss edge.)