_extract_json_payload handles a json/JSON/bare fence, raw JSON and JSON
embedded in prose; any unparseable response or contract violation now
degrades to the deterministic scoring_service instead of raising.
Also guards the response envelope itself (content[0].text).
B3: single home for recommendation scoring
services/recommendation_service.py holds the rules; routers/stats.py and
backend/services/stats_service.py both delegate to it. Unified rules are the
union of the two old copies: same weights/threshold, substring matching
(superset of the old exact match), tolerant key aliases, health_flags rule
kept. Endpoint response contract unchanged.
Plus: Overpass circuit breaker and concurrent zone queries in geo_service -
128 sequential calls per analysis no longer each burn a connect timeout when
the host has no outbound network.
Tests: 152 -> 194 passed.