fix: change exponential rating for distance to be more agressive

README.md

@@ -138,10 +138,10 @@ All scores are precomputed at ingest time for every combination of threshold (5
 Each subcategory *i* contributes a proximity score based on travel time `t` and threshold `T` (both in seconds) using exponential decay:
 
 ```
-score(t, T) = exp(−3 × t / T)
+score(t, T) = exp(−6 × t / T)
 ```
 
-At t = 0 the score is 1.0. At the threshold it is exp(−3) ≈ 0.05 — a POI reachable in exactly the threshold time barely contributes. Close proximity dominates: a third of the threshold away scores ~0.37, halfway scores ~0.22. This ensures that genuinely nearby POIs are rated much more highly than merely reachable ones.
+At t = 0 the score is 1.0. At the threshold it is exp(−6) ≈ 0.002 — essentially zero. Close proximity strongly dominates: a sixth of the threshold away scores ~0.37, a third scores ~0.14. This ensures that only genuinely nearby POIs contribute meaningfully to the score.
 
 The category score aggregates across subcategories **and** across multiple nearby POIs of the same subcategory via a **complement product** weighted by profile-specific importance weights `w_i ∈ [0, 1]`:
 

worker/src/jobs/compute-scores.ts

@@ -248,7 +248,7 @@ export async function handleComputeScores(
             1.0 - COALESCE(pw.weight, ${DEFAULT_SUBCATEGORY_WEIGHT}::float8)
               * CASE
                   WHEN s.travel_time_s IS NULL THEN 0.0
-                  ELSE EXP(-3.0 * s.travel_time_s / (t.threshold_min * 60.0))
+                  ELSE EXP(-6.0 * s.travel_time_s / (t.threshold_min * 60.0))
                 END,
             1e-10
           ))