fix: improve note interactions and markdown LaTeX support

## Bug Fixes

### Note Card Actions
- Fix broken size change functionality (missing state declaration)
- Implement React 19 useOptimistic for instant UI feedback
- Add startTransition for non-blocking updates
- Ensure smooth animations without page refresh
- All note actions now work: pin, archive, color, size, checklist

### Markdown LaTeX Rendering
- Add remark-math and rehype-katex plugins
- Support inline equations with dollar sign syntax
- Support block equations with double dollar sign syntax
- Import KaTeX CSS for proper styling
- Equations now render correctly instead of showing raw LaTeX

## Technical Details

- Replace undefined currentNote references with optimistic state
- Add optimistic updates before server actions for instant feedback
- Use router.refresh() in transitions for smart cache invalidation
- Install remark-math, rehype-katex, and katex packages

## Testing

- Build passes successfully with no TypeScript errors
- Dev server hot-reloads changes correctly

keep-notes/hooks/use-auto-tagging.ts

@@ -16,14 +16,12 @@ export function useAutoTagging({ content, enabled = true }: UseAutoTaggingProps)
   const debouncedContent = useDebounce(content, 1500);
 
   useEffect(() => {
-    // console.log('AutoTagging Effect:', { enabled, contentLength: debouncedContent?.length });
     if (!enabled || !debouncedContent || debouncedContent.length < 10) {
       setSuggestions([]);
       return;
     }
 
     const analyzeContent = async () => {
-      console.log('🚀 Triggering AI analysis for:', debouncedContent.substring(0, 20) + '...');
       setIsAnalyzing(true);
       setError(null);
 
@@ -39,7 +37,6 @@ export function useAutoTagging({ content, enabled = true }: UseAutoTaggingProps)
         }
 
         const data = await response.json();
-        console.log('✅ AI Response:', data);
         setSuggestions(data.tags || []);
       } catch (err) {
         console.error('❌ Auto-tagging error:', err);

keep-notes/hooks/use-reminder-check.ts

@@ -2,11 +2,10 @@
 
 import { useState, useEffect } from 'react';
 import { Note } from '@/lib/types';
-import { useToast } from '@/components/ui/toast';
+import { toast } from 'sonner';
 
 export function useReminderCheck(notes: Note[]) {
   const [notifiedReminders, setNotifiedReminders] = useState<Set<string>>(new Set());
-  const { addToast } = useToast();
 
   useEffect(() => {
     const checkReminders = () => {
@@ -26,7 +25,7 @@ export function useReminderCheck(notes: Note[]) {
           // const audio = new Audio('/notification.mp3');
           // audio.play().catch(e => console.log('Audio play failed', e));
 
-          addToast("🔔 Reminder: " + (note.title || "Untitled Note"), "info");
+          toast.info("🔔 Reminder: " + (note.title || "Untitled Note"));
 
           // Mark as notified in local state
           setNotifiedReminders(prev => new Set(prev).add(note.id));
@@ -41,5 +40,5 @@ export function useReminderCheck(notes: Note[]) {
     const interval = setInterval(checkReminders, 30000);
 
     return () => clearInterval(interval);
-  }, [notes, notifiedReminders, addToast]);
+  }, [notes, notifiedReminders]);
 }