Fix shared logbook access for crew after AI summary sync.

Correct owner detection while the logbook loads, preserve AI summaries on
live-log saves, skip corrupt entry decrypts, and never regenerate keys for
shared logbooks.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/components/LogEntryEditor.tsx

@@ -527,6 +527,8 @@ export default function LogEntryEditor({
   }, [])
 
   useEffect(() => {
+    setCanSignSkipper(false)
+    setCanSignCrew(false)
     getLogbookAccess(logbookId).then((access) => {
       if (!access) return
       setCanSignSkipper(access.isOwner)