diff --git a/gitnexus-web/src/components/GraphCanvas.tsx b/gitnexus-web/src/components/GraphCanvas.tsx
index e06146cdc..d0880dbe1 100644
--- a/gitnexus-web/src/components/GraphCanvas.tsx
+++ b/gitnexus-web/src/components/GraphCanvas.tsx
@@ -272,8 +272,14 @@ export const GraphCanvas = forwardRef<GraphCanvasHandle>((_, ref) => {
       </div>
 
       {/* View Mode Tabs */}
-      <div className="absolute top-4 left-1/2 z-20 flex -translate-x-1/2 gap-1 rounded-lg border border-border-subtle bg-elevated/90 p-1 backdrop-blur-sm">
+      <div
+        role="tablist"
+        aria-label={t('canvas.viewModes.label')}
+        className="absolute top-4 left-1/2 z-20 flex -translate-x-1/2 gap-1 rounded-lg border border-border-subtle bg-elevated/90 p-1 backdrop-blur-sm"
+      >
         <button
+          role="tab"
+          aria-selected={graphViewMode === 'force'}
           onClick={() => handleViewModeChange('force')}
           className={`flex items-center gap-1.5 rounded-md px-3 py-1.5 text-xs font-medium transition-all ${
             graphViewMode === 'force'
@@ -285,6 +291,8 @@ export const GraphCanvas = forwardRef<GraphCanvasHandle>((_, ref) => {
           {t('canvas.viewModes.force')}
         </button>
         <button
+          role="tab"
+          aria-selected={graphViewMode === 'tree'}
           onClick={() => handleViewModeChange('tree')}
           className={`flex items-center gap-1.5 rounded-md px-3 py-1.5 text-xs font-medium transition-all ${
             graphViewMode === 'tree'
@@ -296,6 +304,8 @@ export const GraphCanvas = forwardRef<GraphCanvasHandle>((_, ref) => {
           {t('canvas.viewModes.tree')}
         </button>
         <button
+          role="tab"
+          aria-selected={graphViewMode === 'circles'}
           onClick={() => handleViewModeChange('circles')}
           className={`flex items-center gap-1.5 rounded-md px-3 py-1.5 text-xs font-medium transition-all ${
             graphViewMode === 'circles'
diff --git a/gitnexus-web/src/hooks/useSigma.ts b/gitnexus-web/src/hooks/useSigma.ts
index f2e3cdd77..a2121dad4 100644
--- a/gitnexus-web/src/hooks/useSigma.ts
+++ b/gitnexus-web/src/hooks/useSigma.ts
@@ -586,10 +586,19 @@ export const useSigma = (options: UseSigmaOptions = {}): UseSigmaReturn => {
       edgeReducer: (edge, data) => {
         const res = { ...data };
 
-        // Check edge type visibility first
+        // Check edge type visibility first.
+        // HAS_METHOD / HAS_PROPERTY are Kotlin/Java hierarchy edges not in the
+        // EdgeType union — normalize them so they follow DEFINES / CONTAINS
+        // visibility instead of being silently hidden.
         const visibleTypes = visibleEdgeTypesRef.current;
         if (visibleTypes && data.relationType) {
-          if (!visibleTypes.includes(data.relationType as EdgeType)) {
+          const normalizedType =
+            data.relationType === 'HAS_METHOD'
+              ? 'DEFINES'
+              : data.relationType === 'HAS_PROPERTY'
+                ? 'CONTAINS'
+                : data.relationType;
+          if (!visibleTypes.includes(normalizedType as EdgeType)) {
             res.hidden = true;
             return res;
           }
diff --git a/gitnexus-web/src/lib/graph-adapter.test.ts b/gitnexus-web/src/lib/graph-adapter.test.ts
index a947cca73..4cbb6b8ef 100644
--- a/gitnexus-web/src/lib/graph-adapter.test.ts
+++ b/gitnexus-web/src/lib/graph-adapter.test.ts
@@ -98,8 +98,9 @@ describe('knowledgeGraphToTreeGraphology', () => {
     });
   });
 
-  it('should complete within an acceptable time budget for a medium-sized graph', () => {
+  it('should handle a medium-sized graph without dropping nodes or edges', () => {
     // 2000 nodes + 4000 edges — exercises the adaptive spring iteration path (14 iters).
+    // Structural assertion only: wall-clock timing is too variable across CI machines.
     const nodes: GraphNode[] = Array.from({ length: 2000 }, (_, i) =>
       makeNode(`n${i}`, i % 4 === 0 ? 'Folder' : i % 4 === 1 ? 'File' : 'Function', `node${i}`),
     );
@@ -111,12 +112,14 @@ describe('knowledgeGraphToTreeGraphology', () => {
     }));
     const graph: KnowledgeGraph = { nodes, relationships };
 
-    const start = performance.now();
-    knowledgeGraphToTreeGraphology(graph);
-    const elapsed = performance.now() - start;
+    const sigmaGraph = knowledgeGraphToTreeGraphology(graph);
 
-    // Should complete comfortably within 2 seconds even on slow CI machines.
-    expect(elapsed).toBeLessThan(2000);
+    // All nodes that have a tree-layout position must be present in the output.
+    expect(sigmaGraph.order).toBe(2000);
+    // Every relationship whose source and target both exist should produce an edge.
+    // Self-loops (sourceId === targetId) are excluded — the adapter skips them.
+    const selfLoops = relationships.filter((r) => r.sourceId === r.targetId).length;
+    expect(sigmaGraph.size).toBe(relationships.length - selfLoops);
   });
 });
 
diff --git a/gitnexus-web/src/lib/graph-adapter.ts b/gitnexus-web/src/lib/graph-adapter.ts
index 86bbda11b..bb3f5f11a 100644
--- a/gitnexus-web/src/lib/graph-adapter.ts
+++ b/gitnexus-web/src/lib/graph-adapter.ts
@@ -308,6 +308,11 @@ export const knowledgeGraphToGraphology = (
     // TYPE RELATIONSHIPS - Warm colors (OOP)
     EXTENDS: { color: '#c2410c', sizeMultiplier: 1.0 }, // Orange - extension
     IMPLEMENTS: { color: '#be185d', sizeMultiplier: 0.9 }, // Pink - interface implementation
+
+    // KOTLIN/JAVA HIERARCHY — same hues as their logical equivalents so force
+    // mode renders these consistently with tree/circles view.
+    HAS_METHOD: { color: EDGE_INFO.DEFINES.color, sizeMultiplier: 0.4 }, // Class→Method (≈ DEFINES)
+    HAS_PROPERTY: { color: EDGE_INFO.CONTAINS.color, sizeMultiplier: 0.35 }, // Class→Property (≈ CONTAINS)
   };
 
   // Two-pass insertion so hierarchy/DEFINES edges are drawn first (behind)
diff --git a/gitnexus-web/src/locales/en/graph.json b/gitnexus-web/src/locales/en/graph.json
index 89b5fd0d4..5862253d9 100644
--- a/gitnexus-web/src/locales/en/graph.json
+++ b/gitnexus-web/src/locales/en/graph.json
@@ -113,6 +113,7 @@
   },
   "canvas": {
     "viewModes": {
+      "label": "Graph view mode",
       "force": "Force Graph",
       "tree": "Sequential Layout",
       "circles": "Radial Layout"
diff --git a/gitnexus-web/src/locales/zh-CN/graph.json b/gitnexus-web/src/locales/zh-CN/graph.json
index ab783f178..671c72ba0 100644
--- a/gitnexus-web/src/locales/zh-CN/graph.json
+++ b/gitnexus-web/src/locales/zh-CN/graph.json
@@ -113,6 +113,7 @@
   },
   "canvas": {
     "viewModes": {
+      "label": "图形视图模式",
       "force": "力导向图",
       "tree": "顺序布局",
       "circles": "径向布局"