v0.10.4 fix event date/time functions

frontend/src/components/MobileEventForm.jsx

@@ -253,17 +253,22 @@ export default function MobileEventForm({ event, eventTypes, userGroups, selecte
     finally { setSavingType(false); }
   };
 
-  // When start date changes, match end date
-  useEffect(() => { if(!event) setEd(sd); }, [sd]);
-
-  // When type or start time changes, auto-set end time
+  // When start date or start time changes, update end date/time to maintain duration
   useEffect(() => {
     if(!sd||!st) return;
     const typ = localTypes.find(t=>t.id===Number(typeId));
     const dur = typ?.default_duration_hrs||1;
     const start = buildISO(sd,st);
-    if(start && !event) { setEd(toDateIn(addHours(start,dur))); setEt(toTimeIn(addHours(start,dur))); }
-  }, [typeId, st]);
+    if(!start) return;
+    if(event) {
+      // Editing: only sync end date when start date changes, preserve manual end time
+      setEd(toDateIn(addHours(start, 0)));
+    } else {
+      // New event: always auto-set end to start + duration
+      setEd(toDateIn(addHours(start,dur)));
+      setEt(toTimeIn(addHours(start,dur)));
+    }
+  }, [sd, st, typeId]);
 
   const handle = async () => {
     if(!title.trim()) return toast('Title required','error');