fix(bv): subsample refined wall 이식 + cap outlier loop Python 1:1

Python `extract_walls` (piezophantomtest runners.py:143) 은 MethodDResult 의
antRefined / postRefined (float) 를 우선 사용. 기존 Kotlin 은 정수 ant / post
만 estimateBladderVolume6ch 에 넘겨 1 sample 정밀도 손실 → V3 CenterAligner
per-trace BV 편차 → bv_cv 최대 2% 편차.

주요 변경:
- estimateBladderVolume6ch / estimateBladderVolume: Pair<Double, Double>? 오버로드
  추가. Int 오버로드는 legacy PiezoMonitoring 경로 호환용 (내부에서 Double 로
  toDouble). @JvmName 으로 JVM 시그니처 충돌 회피.
- segmentToDistancesMm(Double, Double) 오버로드 추가.
- repairCenterWallsFor6ch / computeLrRatio 시그니처 Double 로 통일. 인접 채널
  gap=1 선형 보간은 반올림 없이 float 유지 (Python 1:1).
- AlignmentAdvisorV3.buildRecord: Pair(it.antRefined, it.postRefined) 사용
- ClinicalLiveView BV chip: METHOD_D 경로도 refined 사용
- cap ellipse outlier 제거 loop: Python `_bv_core` (bv_estimation.py:1284-1302)
  에 있는 b_si/a_ap>1.3 조건 및 개선 검사 추가 — 이전엔 mean_res 만 봤음
- PrecisionDumpTest: Python vs Kotlin bit-perfect 대조 unit test

검증 (data123 VBT26050202 1CM 첫 trace):
- walls_cross: py=(12.275,50.050,...) == kt=(12.275,50.050,...) 완전 일치
- BV: 50 mL → 43 mL (Python 421 vs Kotlin 464)
- V3 CenterAligner cm=1 bv_cv: 0.265 → 0.260 (Python 0.260 완전 일치)
- cm=3 bv_cv: 0.131 → 0.122 (Python 0.130, 소폭 변경)
- 최종 선택: cm=3 (변함 없음)

남은 43 mL 편차: cap 높이 (bottom_h_mm py=20.06 vs kt=24.02, top_h_mm
py=10.44 vs kt=13.59) — Python 의 `ellipse_cap_height=True` branch
(bv_estimation.py:1337-1358) 아직 미이식. estimate_bv() default 는 이 branch
사용. sagitta 기반 b_si_eff 가중 + _ellipse_cap_h 공식 이식 필요. 후속 세션.

app/src/main/java/com/medithings/vesiscan/managers/AlignmentAdvisorV3.kt

@@ -193,8 +193,10 @@ class CenterAligner(
             if (trBase.size > CH3_INDEX && trBase[CH3_INDEX] != null) ch3Hit++
             val trCross = MethodDRunner.detectMultichannel(
                 tr, methodDParams, applyTgc = true, applyCross = true)
-            val allWalls: List<Pair<Int, Int>?> = trCross.map { r ->
-                r?.let { Pair(it.ant, it.post) }
+            // Python `extract_walls` 는 antRefined/postRefined (subsample) 를 우선 사용.
+            // 정수 ant/post 만 넘기면 최대 1 sample 오차가 D_mm/cap/BV 로 누적 → ~50 mL 편차.
+            val allWalls: List<Pair<Double, Double>?> = trCross.map { r ->
+                r?.let { Pair(it.antRefined, it.postRefined) }
             }
             val bv = estimateBladderVolume6ch(allWalls)
             // Python `position_records`: `if bv is not None: bvs.append(float(bv.volume_ml))`

app/src/main/java/com/medithings/vesiscan/managers/PiezoBVEstimator.kt

@@ -142,8 +142,8 @@ object PiezoHW {
  * Port of bv_estimation.py _repair_center_walls_for_6ch (#21 merge)
  */
 private fun repairCenterWallsFor6ch(
-    centerWalls: List<Pair<Int, Int>?>
-): List<Pair<Int, Int>?> {
+    centerWalls: List<Pair<Double, Double>?>
+): List<Pair<Double, Double>?> {
     val result = centerWalls.toMutableList()
     val valid = result.indices.filter { i ->
         val w = result[i]; w != null
@@ -158,8 +158,9 @@ private fun repairCenterWallsFor6ch(
         if (gap == 1) {
             val pw = result[prevIdx]!!
             val nw = result[nextIdx]!!
-            val ant = ((pw.first + nw.first) / 2.0 + 0.5).toInt()
-            val post = ((pw.second + nw.second) / 2.0 + 0.5).toInt()
+            // Python 1:1: 선형 보간 (반올림 없이 float 유지 — subsample refined 값 보존)
+            val ant = (pw.first + nw.first) / 2.0
+            val post = (pw.second + nw.second) / 2.0
             result[prevIdx + 1] = Pair(ant, post)
             continue
         }
@@ -179,8 +180,8 @@ private fun repairCenterWallsFor6ch(
  * lr_ratio = LR 반축 / AP 반축.
  */
 fun computeLrRatio(
-    centerWalls: List<Pair<Int, Int>?>,
-    lateralWalls: List<Pair<Int, Int>?>,
+    centerWalls: List<Pair<Double, Double>?>,
+    lateralWalls: List<Pair<Double, Double>?>,
     maxRatio: Double = 1.0,
     sensorZMm: DoubleArray = PiezoHW.sensorZMmAll
 ): Double {
@@ -330,9 +331,17 @@ private fun segmentToDistancesMm(
     ant: Int, post: Int,
     dps: Double = PiezoHW.distancePerSample,
     offset: Double = PiezoHW.delayOffsetMm
+): Pair<Double, Double> = segmentToDistancesMm(ant.toDouble(), post.toDouble(), dps, offset)
+
+/** Subsample refined (Double) 오버로드 — Python `extract_walls` 가 refined 우선 사용하는 것과 매칭.
+ *  V3 CenterAligner / Clinical Live BV chip 등 정밀도 요구 경로에서 사용. */
+private fun segmentToDistancesMm(
+    ant: Double, post: Double,
+    dps: Double = PiezoHW.distancePerSample,
+    offset: Double = PiezoHW.delayOffsetMm
 ): Pair<Double, Double> {
-    val d1 = sampleToMm(ant.toDouble(), dps, offset)
-    val d2 = sampleToMm(post.toDouble(), dps, offset)
+    val d1 = sampleToMm(ant, dps, offset)
+    val d2 = sampleToMm(post, dps, offset)
     return Pair(min(d1, d2), max(d1, d2))
 }
 
@@ -475,9 +484,23 @@ const val LUMEN_INSET_FRAC: Double = 0.15
 /**
  * 6ch BV 추정 — center 4채널(CH0~CH3) + lateral 2채널(CH4/CH5)에서 lr_ratio 계산
  * config_6ch.py / bv_estimation.py estimate_bladder_volume_6ch 1:1 포팅
+ *
+ * Int 오버로드 — 기존 legacy PiezoMonitoring 경로 유지용. 정밀도 손실은 없지만
+ * ant/post 를 subsample refine 되기 전 정수 sample index 로 넘김.
+ * Python 1:1 정밀도 원하면 `estimateBladderVolume6ch(List<Pair<Double,Double>?>)`
+ * 오버로드 사용 (refined ant/post 전달).
  */
+@JvmName("estimateBladderVolume6chInt")
 fun estimateBladderVolume6ch(
-    allWalls: List<Pair<Int, Int>?>,   // 6채널 전체 (ant, post), null = invalid
+    allWalls: List<Pair<Int, Int>?>,
+): BVResult? = estimateBladderVolume6ch(
+    allWalls.map { it?.let { p -> Pair(p.first.toDouble(), p.second.toDouble()) } }
+)
+
+/** Double(subsample refined) 오버로드 — Python `extract_walls` 가 refined 우선 사용하는 것과 매칭.
+ *  V3 CenterAligner 등 정밀 검증 경로에서 사용. */
+fun estimateBladderVolume6ch(
+    allWalls: List<Pair<Double, Double>?>,
 ): BVResult? {
     var centerWalls = PiezoHW.centerCh.map { if (it < allWalls.size) allWalls[it] else null }
     centerWalls = repairCenterWallsFor6ch(centerWalls)
@@ -494,6 +517,8 @@ fun estimateBladderVolume6ch(
     )
 }
 
+/** Int 오버로드 — legacy 호환. */
+@JvmName("estimateBladderVolumeInt")
 fun estimateBladderVolume(
     walls: List<Pair<Int, Int>?>,
     distancePerSample: Double = PiezoHW.distancePerSample,
@@ -504,6 +529,30 @@ fun estimateBladderVolume(
     lrRatio: Double = PiezoHW.defaultLrRatio,
     applyAngleCorrection: Boolean = true,
     edgeCh: Int = walls.size - 1,
+    edgeRefChannels: List<Int> = listOf(walls.size - 2, walls.size - 3),
+): BVResult? = estimateBladderVolume(
+    walls = walls.map { it?.let { p -> Pair(p.first.toDouble(), p.second.toDouble()) } },
+    distancePerSample = distancePerSample,
+    delayOffsetMm = delayOffsetMm,
+    sensorZMm = sensorZMm,
+    degreeDeg = degreeDeg,
+    areaK = areaK,
+    lrRatio = lrRatio,
+    applyAngleCorrection = applyAngleCorrection,
+    edgeCh = edgeCh,
+    edgeRefChannels = edgeRefChannels,
+)
+
+fun estimateBladderVolume(
+    walls: List<Pair<Double, Double>?>,
+    distancePerSample: Double = PiezoHW.distancePerSample,
+    delayOffsetMm: Double = PiezoHW.delayOffsetMm,
+    sensorZMm: DoubleArray = PiezoHW.sensorZMm,
+    degreeDeg: DoubleArray = PiezoHW.degree,
+    areaK: Double = PiezoHW.areaK,
+    lrRatio: Double = PiezoHW.defaultLrRatio,
+    applyAngleCorrection: Boolean = true,
+    edgeCh: Int = walls.size - 1,
     edgeRefChannels: List<Int> = listOf(walls.size - 2, walls.size - 3)
 ): BVResult? {
 
@@ -513,7 +562,7 @@ fun estimateBladderVolume(
         val wEdge = walls[edgeCh]
         if (wEdge != null) {
             val lEdge = wEdge.second - wEdge.first
-            val refLens = mutableListOf<Int>()
+            val refLens = mutableListOf<Double>()
             for (ci in edgeRefChannels) {
                 if (ci in walls.indices) {
                     val w = walls[ci]
@@ -521,7 +570,7 @@ fun estimateBladderVolume(
                 }
             }
             val minRef = refLens.minOrNull()
-            if (minRef != null && lEdge.toDouble() < 0.9 * minRef.toDouble()) {
+            if (minRef != null && lEdge < 0.9 * minRef) {
                 edgeIsShort = true
             }
         }
@@ -654,19 +703,26 @@ fun estimateBladderVolume(
             var resid = fit[4] as DoubleArray
             var meanRes = resid.average()
 
-            // 반복 outlier 제거: worst 점 하나씩, 최소 5점 유지
-            while (meanRes > ellipseCostThr && keep.count { it } > 5) {
+            // Python `_bv_core` outlier 제거 loop (bv_estimation.py:1284-1302) 1:1:
+            //   조건 : mean_res > 0.5 OR b_si/a_ap > 1.3
+            //   accept: 새 fit 이 mean_res OR ratio 둘 중 하나라도 개선
+            fun needsRemoval() = meanRes > ellipseCostThr || bSi / aAp > 1.3
+
+            while (needsRemoval() && keep.count { it } > 5) {
                 val worstLocal = resid.indices.maxByOrNull { resid[it] } ?: break
                 val activeIndices = keep.indices.filter { keep[it] }
                 keep[activeIndices[worstLocal]] = false
                 val keptY = keep.indices.filter { keep[it] }.map { allYw[it] }.toDoubleArray()
                 val keptZ = keep.indices.filter { keep[it] }.map { allZw[it] }.toDoubleArray()
                 val fit2 = fitEllipsePts(keptY, keptZ) ?: break
-                val meanRes2 = (fit2[4] as DoubleArray).average()
-                if (meanRes2 < meanRes) {
-                    y0 = fit2[0] as Double; z0 = fit2[1] as Double
-                    bSi = fit2[2] as Double; aAp = fit2[3] as Double
-                    resid = fit2[4] as DoubleArray; meanRes = meanRes2
+                val y02 = fit2[0] as Double; val z02 = fit2[1] as Double
+                val bSi2 = fit2[2] as Double; val aAp2 = fit2[3] as Double
+                val resid2 = fit2[4] as DoubleArray
+                val meanRes2 = resid2.average()
+                val improved = meanRes2 < meanRes || (bSi2 / aAp2) < (bSi / aAp)
+                if (improved) {
+                    y0 = y02; z0 = z02; bSi = bSi2; aAp = aAp2
+                    resid = resid2; meanRes = meanRes2
                 } else break
             }
 
@@ -685,10 +741,12 @@ fun estimateBladderVolume(
         }
     }
 
-    // shrink_bottom_cap=true (Python default) — posterior arc 원 fit + sagitta shrink 로
-    //   R_eff 공유 곡률 산출. 성공 시 both caps 높이를 정규화 (자유 b_si 제거).
+    // shrink_bottom_cap=true — posterior arc 원 fit + sagitta shrink 로 R_eff 공유 곡률.
+    //   TODO: Python default `ellipse_cap_height=True` branch (bv_estimation.py:1337-1358)
+    //         는 아직 미이식. estimate_bv() 는 그 branch 를 쓰므로 cap 높이 3-5 mm 편차
+    //         (bottom_h_mm py=20.06 vs kt=24.02) 잔존. 다음 세션에서 이식 예정.
     val rEffCap: Double? =
-        if (cApPrior != null) shrinkSiRadius(yWallPost, zWallPost, cApPrior) else null
+        if (cApPrior != null) shrinkSiRadius(yWallPost, zWallPost, cApPrior!!) else null
     if (rEffCap != null) {
         hCapBot = minorCapHeight(rEffCap, aCapS[0])
         hCapTop = minorCapHeight(rEffCap, aCapS[n - 1])

app/src/main/java/com/medithings/vesiscan/ui/views/clinical/ClinicalLiveView.kt

@@ -126,6 +126,8 @@ fun ClinicalLiveView(appState: AppState) {
                 bvFrustum = com.medithings.vesiscan.managers.estimateBladderVolume6ch(channelWalls)
                     ?.volumeMl?.takeIf { it.isFinite() && it > 0 }
                 // BV[METHOD_D] = MethodD walls (apply_cross=true) + frustum.
+                //   Python 1:1 정밀도를 위해 antRefined/postRefined (Double) 사용
+                //   (integer ant/post 만 넘기면 subsample 손실로 ~50 mL 편차 발생).
                 val signalsD = (0..5).map { ch ->
                     channels.find { it.channel == ch }?.buffer?.let { buf ->
                         DoubleArray(buf.size) { buf[it].toDouble() }
@@ -133,8 +135,8 @@ fun ClinicalLiveView(appState: AppState) {
                 }
                 val mdResults = com.medithings.vesiscan.walldetect.MethodDRunner
                     .detectMultichannel(signalsD, applyCross = true)
-                val mdWalls: List<Pair<Int, Int>?> = mdResults.map { r ->
-                    r?.let { Pair(it.ant, it.post) }
+                val mdWalls: List<Pair<Double, Double>?> = mdResults.map { r ->
+                    r?.let { Pair(it.antRefined, it.postRefined) }
                 }
                 bvMethodD = com.medithings.vesiscan.managers.estimateBladderVolume6ch(mdWalls)
                     ?.volumeMl?.takeIf { it.isFinite() && it > 0 }