beankeeper-bridge: no consumer wired — add ledger import path

[elasticdotventures]

The beankeeper-bridge crate (PR #122) provides OFX→double-entry conversion producing balanced Entry pairs, but no consumer currently wires it into the ledger import pipeline. There is no code that reads an OFX statement, calls the bridge, and posts the result to a beankeeper Ledger.

This is a gap between the bridge capability and actual usability — the bridge exists but is unreachable from any user-facing workflow.