Add create_runway_router() following the hub-core factory pattern,
expose GET /runway/summary and /runway/monthly-burn via create_app,
and add finhub serve for local operation.
Link the DB-first onboarding workstream to FIN-WP-0000-repo-integration.md,
finish agent orientation (rules stubs, remove first-session), add repo
classification, and close all four custodian onboarding tasks.