Expands scope to cover both remaining egress hotspot tasks from #117:
- Replaces the named-helper design with a flat provisioned-wins merge
(provider routes own their hosts; manifest fills gaps; no upgrade or
conflict-detection logic needed).
- Adds _route_to_yaml_fields as the single authoritative EgressRoute→Route
mapping to prevent silent type drift between host and addon.
- Notes that the mitmproxy pure-function split is already clean (decide +
is_git_push_request) and requires no structural change.
didericis-claude