fix(map): fill 3-tier LOD로 타일 seam 해결

- 심해 fill 폴리곤이 globe 타일 경계에서 seam 아티팩트 발생
- bathymetry-fill: z3-7 (depth >= -2000, 천해만)
- bathymetry-fill-medium: z7-9 (depth >= -4000)
- bathymetry-fill-deep: z9+ (전체 depth)
- applyDepthGradient: 3개 fill 레이어 모두 적용

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/widgets/map3d/hooks/useMapStyleSettings.ts

@@ -102,7 +102,6 @@ function applyWaterBaseColor(map: maplibregl.Map, fillColor: string) {
 }
 
 function applyDepthGradient(map: maplibregl.Map, stops: DepthColorStop[]) {
-  if (!map.getLayer('bathymetry-fill')) return;
   const depth = ['to-number', ['get', 'depth']];
   const sorted = [...stops].sort((a, b) => a.depth - b.depth);
   if (sorted.length === 0) return;
@@ -115,10 +114,13 @@ function applyDepthGradient(map: maplibregl.Map, stops: DepthColorStop[]) {
   if (shallowest.depth < 0) {
     expr.push(0, lightenHex(shallowest.color, 1.8));
   }
-  try {
+  for (const layerId of ['bathymetry-fill', 'bathymetry-fill-medium', 'bathymetry-fill-deep']) {
-    map.setPaintProperty('bathymetry-fill', 'fill-color', expr as never);
+    if (!map.getLayer(layerId)) continue;
-  } catch {
+    try {
-    // ignore
+      map.setPaintProperty(layerId, 'fill-color', expr as never);
+    } catch {
+      // ignore
+    }
   }
 }
 

apps/web/src/widgets/map3d/layers/bathymetry.ts

@@ -10,7 +10,9 @@ export const SHALLOW_WATER_FILL_DEFAULT = '#14606e';
 export const SHALLOW_WATER_LINE_DEFAULT = '#114f5c';
 
 const BATHY_ZOOM_RANGES: BathyZoomRange[] = [
-  { id: 'bathymetry-fill', mercator: [3, 24], globe: [3, 24] },
+  { id: 'bathymetry-fill', mercator: [3, 7], globe: [3, 7] },
+  { id: 'bathymetry-fill-medium', mercator: [7, 9], globe: [7, 9] },
+  { id: 'bathymetry-fill-deep', mercator: [9, 24], globe: [9, 24] },
   { id: 'bathymetry-borders-major', mercator: [3, 7], globe: [3, 7] },
   { id: 'bathymetry-borders', mercator: [7, 24], globe: [7, 24] },
   { id: 'bathymetry-lines-coarse', mercator: [5, 7], globe: [5, 7] },
@@ -111,18 +113,47 @@ export function injectOceanBathymetryLayers(style: StyleSpecification, maptilerK
   const depthIn = (depths: number[]) =>
     ['in', depth, ['literal', depths]] as unknown[];
 
-  // === Fill (contour polygons) — 전체 depth, 줌에 따라 자연스럽게 표시 ===
+  // === Fill (contour polygons) — 3-tier LOD ===
+  // 심해 폴리곤이 여러 벡터 타일에 걸칠 때 globe tessellation 타일 경계에서
+  // seam 아티팩트 발생 → 줌아웃에서는 shallow만, 줌인에서 점진적으로 심해 포함
+  const bathyFillPaint = {
+    'fill-color': bathyFillColor,
+    'fill-opacity': ['interpolate', ['linear'], ['zoom'], 0, 0.9, 5, 0.88, 8, 0.84, 10, 0.78],
+  };
+
+  // z3-7: depth >= -2000 (천해만 — 타일 seam 방지)
   const bathyFill: LayerSpecification = {
     id: 'bathymetry-fill',
     type: 'fill',
     source: oceanSourceId,
     'source-layer': 'contour',
     minzoom: 3,
+    maxzoom: 7,
+    filter: ['>=', depth, -2000] as unknown as unknown[],
+    paint: bathyFillPaint,
+  } as unknown as LayerSpecification;
+
+  // z7-9: depth >= -4000 (중심해 포함)
+  const bathyFillMedium: LayerSpecification = {
+    id: 'bathymetry-fill-medium',
+    type: 'fill',
+    source: oceanSourceId,
+    'source-layer': 'contour',
+    minzoom: 7,
+    maxzoom: 9,
+    filter: ['>=', depth, -4000] as unknown as unknown[],
+    paint: bathyFillPaint,
+  } as unknown as LayerSpecification;
+
+  // z9+: 전체 depth (풀 디테일 — 뷰포트가 작아 타일 seam 무관)
+  const bathyFillDeep: LayerSpecification = {
+    id: 'bathymetry-fill-deep',
+    type: 'fill',
+    source: oceanSourceId,
+    'source-layer': 'contour',
+    minzoom: 9,
     maxzoom: 24,
-    paint: {
+    paint: bathyFillPaint,
-      'fill-color': bathyFillColor,
-      'fill-opacity': ['interpolate', ['linear'], ['zoom'], 0, 0.9, 5, 0.88, 8, 0.84, 10, 0.78],
-    },
   } as unknown as LayerSpecification;
 
   // === Borders (contour polygon edges) — 2-tier LOD ===
@@ -326,6 +357,8 @@ export function injectOceanBathymetryLayers(style: StyleSpecification, maptilerK
 
   const toInsert = [
     bathyFill,
+    bathyFillMedium,
+    bathyFillDeep,
     bathyBordersMajor,
     bathyBorders,
     bathyLinesCoarse,