v0.9.9: Add foreign currency (USD) PDF importer for Banco de Chile (#33)

* Add foreign currency (USD) PDF importer for Banco de Chile

Support for Banco de Chile foreign currency checking account PDF
statements (MONEDA EXTRANJERA). These statements use comma as decimal
separator (100,00) and a different header format (SR(A)(ES), MONEDA
field) compared to CLP cartolas.

New extractor handles USD amount parsing, currency detection from
header, document number (N° DOCTO) metadata preservation, and
credit/debit classification for foreign currency transactions.

* Include currency in filename for foreign currency accounts

Foreign accounts generate filenames like
"2025-07-01_banco_chile_usd_59012345678.pdf" to distinguish them
from CLP accounts.

* Bump version to 0.9.9