docs: actualizar .gitignore y CLAUDE.md

- Agregar knowledges/data/ a .gitignore (DB no se commitea)
- Agregar knowledges/ a estructura en CLAUDE.md
- Los .md compartidos sí se commitean
- Issue 0018: Shared Knowledge (fase 7)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.gitignore

@@ -9,6 +9,9 @@ run/*.txt
 
 logs/
 
+# Shared knowledge DB (markdown files are tracked, DB is rebuilt on sync)
+knowledges/data/
+
 # E2E tests
 e2e/node_modules/
 e2e/test-results/