When Objective mapping coverage falls below 50% of competitors in the radius,
fall back to rosreestr_deals JOIN on the parcel's cadastral quarter. Audit shows
237/237 EKB quarters (100%) have rosreestr data for the last 12 months, compared
to <20% Objective coverage before bulk mapping.
- velocity.py: add _compute_rosreestr_fallback(), _OBJECTIVE_COVERAGE_MIN_RATIO
constant, velocity_source field on VelocityResult (objective/rosreestr_fallback/none)
- parcels.py: extract cad_quarter from cad_num, pass to compute_velocity
- site-finder.ts: add velocity_source field to Velocity interface
- VelocityBlock.tsx: badge "Источник: квартальные сделки" when rosreestr_fallback
Epic #271 item #17
Replace INNER JOIN on objective_complex_mapping with LEFT JOIN approach:
competitors without mapping now return velocity=0 with
velocity_data_available=False instead of being silently dropped.
UI: VelocityBlock shows 'нет данных velocity' badge when flag is False
and hides the gauge (meaningless zero). TS type updated (additive optional
field, backward compat).
Audit (EKB, region_cd=66): mapped=129, unmapped=1387, total=1516.
Closes#271 item #10
