feat: MVP-3 Sprint 1 - Usage tracking, smart dashboard, scoring boost

## Registro de Uso
- Nuevo modelo NoteUsage en Prisma
- Tipos de eventos: view, search_click, related_click, link_click, copy_command, copy_snippet
- Funciones: trackNoteUsage, getUsageStats, getRecentlyUsedNotes
- localStorage: recentlyViewed (últimas 10 notas)
- Rastreo de copias en markdown-content.tsx

## Dashboard Rediseñado
- 5 bloques: Recientes, Más usadas, Comandos recientes, Snippets recientes, Según actividad
- Nuevo src/lib/dashboard.ts con getDashboardData()
- Recomendaciones basadas en recentlyViewed

## Scoring con Uso Real
- search.ts: +1 per 5 views (max +3), +2 recency boost
- related.ts: mismo sistema de usage boost
- No eclipsa match textual fuerte

## Tests
- 110 tests pasando (usage, dashboard, related, search)

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

src/app/page.tsx

@@ -1,37 +1,19 @@
-import { prisma } from '@/lib/prisma'
 import { Dashboard } from '@/components/dashboard'
-import { NoteType } from '@/types/note'
-
-async function getNotes() {
-  const notes = await prisma.note.findMany({
-    include: { tags: { include: { tag: true } } },
-    orderBy: { updatedAt: 'desc' },
-  })
-  return notes
-}
+import { getDashboardData } from '@/lib/dashboard'
 
 export default async function HomePage() {
-  const allNotes = await getNotes()
-
-  const notesWithTags = allNotes.map(note => ({
-    ...note,
-    createdAt: note.createdAt.toISOString(),
-    updatedAt: note.updatedAt.toISOString(),
-    type: note.type as NoteType,
-    tags: note.tags.map(nt => ({ tag: nt.tag })),
-  }))
-
-  const recentNotes = notesWithTags.slice(0, 6)
-  const favoriteNotes = notesWithTags.filter(n => n.isFavorite)
-  const pinnedNotes = notesWithTags.filter(n => n.isPinned)
+  const data = await getDashboardData(6)
 
   return (
     <main className="container mx-auto pt-8 px-4">
       <Dashboard
-        recentNotes={recentNotes}
-        favoriteNotes={favoriteNotes}
-        pinnedNotes={pinnedNotes}
+        recentNotes={data.recentNotes}
+        mostUsedNotes={data.mostUsedNotes}
+        recentCommands={data.recentCommands}
+        recentSnippets={data.recentSnippets}
+        activityBasedNotes={data.activityBasedNotes}
+        hasActivity={data.hasActivity}
       />
     </main>
   )
-}
+}