actual_deals carried non-market/broken rows (floor:100, ~39.7K/m² for 125m²)
that fed dkp_corridor + expected_sold with noise. Add absolute guard-bands
for EKB vtorichka:
- ppm² in [50K, 800K] (market ~100-400K, premium up to ~680K; below/above is
not arms-length — shares, encumbered, typos)
- floor in [1, 60] and floor <= total_floors (floor:100 / 30-in-a-5-storey).
_fetch_deals filters rows via _is_plausible_deal (display + downstream);
_fetch_dkp_corridor adds the ppm² band to its SQL (expected_sold corridor).
Relative Tukey outlier filter on listings unchanged.
Refs #699
