feat: funciones Bash — install_nbconvert, notebook_to_pdf, export_analysis_pdfs

Infra: install_nbconvert (instala nbconvert+deps), notebook_to_pdf (convierte .ipynb a PDF).
Pipeline: export_analysis_pdfs (exporta todos los notebooks de analysis/ a PDF).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bash/functions/infra/install_nbconvert.md

@@ -0,0 +1,32 @@
+---
+name: install_nbconvert
+kind: function
+lang: bash
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "install_nbconvert(project_dir: string) -> void"
+description: "Instala nbconvert y playwright con chromium en un proyecto uv existente. Idempotente: uv add no reinstala si los paquetes ya estan presentes."
+tags: [jupyter, nbconvert, pdf, export, playwright, python, uv]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: []
+tested: false
+tests: []
+test_file_path: ""
+file_path: "bash/functions/infra/install_nbconvert.sh"
+---
+
+## Ejemplo
+
+```bash
+source install_nbconvert.sh
+install_nbconvert /home/lucas/analysis/finanzas
+```
+
+## Notas
+
+Requiere que el venv ya exista (usa `init_uv_venv` antes). La instalacion de chromium via `uv run playwright install chromium` puede tardar la primera vez. La salida de playwright se suprime si tiene exito — solo se muestra si hay un error.