feat: MVP-5 P2 - Export/Import, Settings, Tests y Validaciones

- Ticket 10: Navegación completa de listas por teclado (↑↓ Enter E F P)
- Ticket 13: Historial de navegación contextual con recent-context-list
- Ticket 17: Exportación mejorada a Markdown con frontmatter
- Ticket 18: Exportación HTML simple y legible
- Ticket 19: Importador Markdown mejorado con frontmatter, tags, wiki links
- Ticket 20: Importador Obsidian-compatible (wiki links, #tags inline)
- Ticket 21: Centro de respaldo y portabilidad en Settings
- Ticket 22: Configuración visible de feature flags
- Ticket 24: Tests de command palette y captura externa
- Ticket 25: Harden de validaciones y límites (50MB backup, 10K notas, etc)

src/components/keyboard-navigable-note-list.tsx

@@ -0,0 +1,86 @@
+'use client'
+
+import { useCallback } from 'react'
+import { Note } from '@/types/note'
+import { NoteCard } from './note-card'
+import { useNoteListKeyboard } from '@/hooks/use-note-list-keyboard'
+import { toast } from 'sonner'
+
+interface KeyboardNavigableNoteListProps {
+  notes: Note[]
+  onEdit?: (noteId: string) => void
+}
+
+export function KeyboardNavigableNoteList({
+  notes,
+  onEdit,
+}: KeyboardNavigableNoteListProps) {
+  const handleFavorite = useCallback(async (noteId: string) => {
+    try {
+      const res = await fetch(`/api/notes/${noteId}`, {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ isFavorite: true }),
+      })
+      if (res.ok) {
+        toast.success('Añadido a favoritos')
+        window.location.reload()
+      }
+    } catch {
+      toast.error('Error al añadir a favoritos')
+    }
+  }, [])
+
+  const handlePin = useCallback(async (noteId: string) => {
+    try {
+      const res = await fetch(`/api/notes/${noteId}`, {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ isPinned: true }),
+      })
+      if (res.ok) {
+        toast.success('Nota fijada')
+        window.location.reload()
+      }
+    } catch {
+      toast.error('Error al fijar nota')
+    }
+  }, [])
+
+  const { selectedIndex } = useNoteListKeyboard({
+    notes,
+    onEdit,
+    onFavorite: handleFavorite,
+    onPin: handlePin,
+  })
+
+  if (notes.length === 0) {
+    return (
+      <div className="text-center py-12 text-gray-500">
+        <p className="text-lg">No hay notas todavía</p>
+        <p className="text-sm">Crea tu primera nota para comenzar</p>
+      </div>
+    )
+  }
+
+  return (
+    <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+      {notes.map((note, index) => (
+        <div
+          key={note.id}
+          className={`relative ${index === selectedIndex ? 'ring-2 ring-primary ring-offset-2 rounded-lg' : ''}`}
+          data-selected={index === selectedIndex}
+        >
+          <NoteCard note={note} />
+          {index === selectedIndex && (
+            <div className="absolute bottom-2 right-2 flex gap-1">
+              <span className="px-1.5 py-0.5 bg-muted text-xs rounded text-muted-foreground">
+                Enter: abrir | E: editar | F: favoritar | P: fijar
+              </span>
+            </div>
+          )}
+        </div>
+      ))}
+    </div>
+  )
+}