950-E1: app/tasks/newbuilding_enrich_backfill.py selects houses linked to
ext_source='cian_newbuilding' with a fetchable cian_zhk_url and runs the existing
fetch_newbuilding + save_newbuilding_enrichment over each, populating
houses_price_dynamics + house_reliability_checks (+ house_reviews when present).
- Idempotent + resumable: skips already-enriched houses; force= re-run dup-safe
(price_dynamics UPSERT via dim_key, reliability dedup guard with id-DESC
tiebreaker, reviews ON CONFLICT (source,ext_review_id)).
- Anti-bot aware: get_scraper_delay('cian') + jitter, SAVEPOINT-per-house
(one captcha/failure logs + continues, never aborts the batch).
- limit= for bounded proof runs; sizing counters (total/fetchable/pending).
Fix cian_newbuilding._extract_transport_rate: cian transportAccessibilityRate
drifted to a nested dict and broke save_newbuilding_enrichment's CAST bind on
LIVE data (cannot adapt type 'dict') — coerce dict/float/bad -> int|None
(bool excluded before int). Fixes the live enrichment crash, not just backfill.
house_reviews stays ~0 for now: cian reviews are in a separate XHR, not the ЖК
initialState — extending fetch_newbuilding for them is a documented follow-up.
Tested: 8 new unit tests; isolated-DB proof-run landed 6 price_dynamics + 1
reliability row, idempotency proven across re-runs. Refs #972.
