feat: bound climb detection by matched official climbs

Detected climbs no longer absorb an official climb's range: official climbs
matched to the route by coordinates claim their stored start/end range, and
climb detection now runs only in the free regions around them. On ride 263 a
single absorbed Cat 2 ascent is split so creating a first-half official climb
lets the second half be detected on its own.

- ride: add Range, freeRegions, and DetectClimbs(claimed); exclude claimed
  ranges so a climb never overlaps one
- official_climb: MatchClimb now bounds-matches purely by coordinates without
  needing a detected climb; extract geo.Nearest shared helper
- rideanalysis: Analyze builds claimed climbs from matched official climbs and
  detects only in free regions; render official vs unmatched climbs separately

1 files changed, 23 insertions, 43 deletions

diff --git a/official_climb/matcher.go b/official_climb/matcher.go
index e7b51de..faf51a7 100644
--- a/official_climb/matcher.go
+++ b/official_climb/matcher.go
@@ -4,52 +4,32 @@ import (
 	"math"
 
 	"github.com/jftuga/geodist"
-	"github.com/martinlehoux/biking_home/ride"
+	"github.com/martinlehoux/biking_home/geo"
 )
 
-func MatchClimb(route ride.Ride, climb ride.Climb, officialClimbs []OfficialClimb, policy MatchPolicy) (OfficialClimb, bool) {
-	if policy.Validate() != nil {
-		return OfficialClimb{}, false
-	}
-	bestDistance := math.Inf(1)
-	var best OfficialClimb
-	found := false
-	for _, official := range officialClimbs {
-		startIndex, startDistance := nearestRoutePoint(route, official.StartCoord)
-		endIndex, endDistance := nearestRoutePoint(route, official.EndCoord)
-		if startDistance > policy.EndpointRadiusM || endDistance > policy.EndpointRadiusM {
-			continue
-		}
-		if startIndex >= endIndex {
-			continue
-		}
-		if endIndex < climb.StartIndex() || startIndex > climb.EndIndex() {
-			continue
-		}
-		totalDistance := startDistance + endDistance
-		if totalDistance < bestDistance || (totalDistance == bestDistance && (!found || official.ID < best.ID)) {
-			best = official
-			bestDistance = totalDistance
-			found = true
-		}
-	}
-	return best, found
+// MatchedClimb is an official climb that lies on a route, together with the
+// route point indexes of its start and end. It lets the climb detector know
+// which segment of the route is already claimed by an official climb.
+type MatchedClimb struct {
+	OfficialClimb
+	StartIndex int
+	EndIndex   int
 }
 
-func nearestRoutePoint(route ride.Ride, target geodist.Coord) (int, float64) {
-	bestIndex := 0
-	bestDistance := math.Inf(1)
-	for index := 0; index < route.Len(); index++ {
-		distance := distanceM(route.Coord(index), target)
-		if distance < bestDistance {
-			bestIndex = index
-			bestDistance = distance
-		}
+// MatchClimb matches an official climb against a route purely by
+// coordinates: both the start and end coordinates must be within radiusM of a
+// route point, and the matched start point must precede the matched end point.
+func MatchClimb(route []geodist.Coord, official OfficialClimb, radiusM float64) (MatchedClimb, bool) {
+	if math.IsNaN(radiusM) || math.IsInf(radiusM, 0) || radiusM <= 0 {
+		return MatchedClimb{}, false
 	}
-	return bestIndex, bestDistance
-}
-
-func distanceM(a, b geodist.Coord) float64 {
-	_, distanceKm := geodist.HaversineDistance(a, b)
-	return distanceKm * 1000
+	startIndex, startDistance := geo.Nearest(route, official.StartCoord)
+	endIndex, endDistance := geo.Nearest(route, official.EndCoord)
+	if startDistance > radiusM || endDistance > radiusM {
+		return MatchedClimb{}, false
+	}
+	if startIndex >= endIndex {
+		return MatchedClimb{}, false
+	}
+	return MatchedClimb{OfficialClimb: official, StartIndex: startIndex, EndIndex: endIndex}, true
 }