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)

__tests__/external-capture.test.ts

@@ -0,0 +1,36 @@
+import { generateBookmarklet, encodeCapturePayload, CapturePayload } from '@/lib/external-capture'
+
+describe('external-capture', () => {
+  describe('generateBookmarklet', () => {
+    it('generates a valid javascript bookmarklet string', () => {
+      const bookmarklet = generateBookmarklet()
+      expect(bookmarklet).toContain('javascript:')
+      expect(bookmarklet.length).toBeGreaterThan(0)
+    })
+
+    it('contains the capture URL', () => {
+      const bookmarklet = generateBookmarklet()
+      expect(bookmarklet).toContain('capture')
+    })
+  })
+
+  describe('encodeCapturePayload', () => {
+    it('encodes title in params', () => {
+      const payload: CapturePayload = { title: 'Test Note', url: '', selection: '' }
+      const encoded = encodeCapturePayload(payload)
+      expect(encoded).toContain('title=Test')
+    })
+
+    it('encodes url in params', () => {
+      const payload: CapturePayload = { title: '', url: 'https://example.com', selection: '' }
+      const encoded = encodeCapturePayload(payload)
+      expect(encoded).toContain('url=https%3A%2F%2Fexample.com')
+    })
+
+    it('encodes selection in params', () => {
+      const payload: CapturePayload = { title: '', url: '', selection: 'Selected text' }
+      const encoded = encodeCapturePayload(payload)
+      expect(encoded).toContain('selection=Selected')
+    })
+  })
+})