fix: convert Map to Record for server-client boundary, remove dead currentUser prop

- WeatherBoard: change previousEntries type from Map<string, PreviousEntry> to Record<string, PreviousEntry> and update lookup from .get() to bracket notation
- page.tsx: wrap previousEntries with Object.fromEntries() before passing as prop, remove unused currentUser prop
- WeatherCard: remove spurious eslint-disable-next-line comment for non-existent rule react-hooks/set-state-in-effect

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/weather/WeatherCard.tsx

@@ -69,7 +69,6 @@ export function WeatherCard({ sessionId, currentUserId, entry, canEdit, previous
 
   // Sync local state with props when they change (e.g., from SSE refresh)
   useEffect(() => {
-    // eslint-disable-next-line react-hooks/set-state-in-effect
     setNotes(entry.notes || '');
     setPerformanceEmoji(entry.performanceEmoji || null);
     setMoralEmoji(entry.moralEmoji || null);