feat: connect Finance services to platform edge

[iPior]

Summary

• attaches the Finance web service to the external pior_edge network as finance-web
• attaches the Finance API service to pior_edge as finance-api
• keeps the existing localhost port bindings during the migration
• leaves the MCP server and private database networking unchanged
• documents the platform edge contract

Why

The containerized platform Caddy routes Finance traffic to finance-web:80 and finance-api:3000. Those aliases must exist on the shared edge network before Finance can be tested through the new Caddy instance.

Impact

The current host-Caddy deployment remains operational because the existing 127.0.0.1:8080 web binding and 127.0.0.1:3000 API binding are retained. This PR only adds a second, private Docker-network path for the test edge proxy.

Validation after merge

cd /opt/finlens
git pull
docker compose config --quiet
docker compose up -d --build

docker network inspect pior_edge
curl -i -H 'Host: finance.szarans.ca' http://127.0.0.1:8088
curl -i -H 'Host: finance.ts.szarans.ca' http://127.0.0.1:8088

Expected behavior:

• the Finance web page is returned through both hostnames
• requests under /api/* are routed to the API container
• the existing production route remains unchanged