fix: use radial force for knowledge graph

src/renderer/src/KnowledgeGraphChart.tsx

@@ -176,19 +176,29 @@ function createPresentation(
       }))
     },
     layout: {
-      type: 'circular',
+      type: 'd3-force',
       animate: false,
-      ordering: 'topology',
-      startAngle: -Math.PI / 2,
-      endAngle: Math.PI * 1.5,
-      clockwise: true,
-      divisions: 1,
-      angleRatio: 1,
+      centerStrength: 0.8,
+      linkDistance: dense ? 44 : 64,
+      edgeStrength: dense ? 0.28 : 0.4,
+      edgeIterations: 2,
+      nodeStrength: dense ? -45 : -70,
+      theta: 0.8,
+      preventOverlap: true,
+      collideStrength: 0.9,
+      collideIterations: 2,
       nodeSize: (datum: Record<string, unknown>) => {
         const metadata = datum.data as G6NodeMetadata | undefined
         return metadata?.size ?? 24
       },
-      nodeSpacing: dense ? 20 : 28
+      nodeSpacing: dense ? 10 : 14,
+      x: false,
+      y: false,
+      radialRadius: 0,
+      radialStrength: dense ? 0.055 : 0.04,
+      alphaMin: 0.015,
+      alphaDecay: 0.045,
+      velocityDecay: 0.42
     },
     node: {
       type: 'circle',
@@ -474,6 +484,13 @@ export function KnowledgeGraphChart({
           return
         }
         renderedRevisionRef.current = dataRevision
+        await graph.fitView(
+          {
+            when: 'always',
+            direction: 'both'
+          },
+          false
+        )
         appliedZoomRef.current = graph.getZoom()
         const states = Object.fromEntries(
           nodesRef.current.map((node) => [

src/renderer/src/KnowledgeWorkspace.test.tsx

@@ -18,6 +18,7 @@ const g6Mock = vi.hoisted(() => {
   const graph = {
     destroy: vi.fn(),
     draw: vi.fn(async () => undefined),
+    fitView: vi.fn(async () => undefined),
     getElementPosition: vi.fn(() => [240, 320]),
     getZoom: vi.fn(() => 1),
     off: vi.fn((eventName: string) => handlers.delete(eventName)),
@@ -472,9 +473,13 @@ describe('KnowledgeWorkspace', () => {
         },
         layout: expect.objectContaining({
           animate: false,
-          angleRatio: 1,
-          ordering: 'topology',
-          type: 'circular'
+          centerStrength: 0.8,
+          linkDistance: 64,
+          nodeStrength: -70,
+          preventOverlap: true,
+          radialRadius: 0,
+          radialStrength: 0.04,
+          type: 'd3-force'
         }),
         behaviors: expect.arrayContaining([
           'drag-canvas',
@@ -500,6 +505,13 @@ describe('KnowledgeWorkspace', () => {
       },
       false
     )
+    expect(g6Mock.graph.fitView).toHaveBeenCalledWith(
+      {
+        when: 'always',
+        direction: 'both'
+      },
+      false
+    )
     const stableRenderCallCount = g6Mock.graph.render.mock.calls.length
     rerender(<KnowledgeWorkspace {...createProps({ onMoveNode })} />)
     expect(g6Mock.graph.render).toHaveBeenCalledTimes(stableRenderCallCount)
@@ -661,9 +673,13 @@ describe('KnowledgeWorkspace', () => {
         }),
         layout: expect.objectContaining({
           animate: false,
-          nodeSpacing: 20,
-          ordering: 'topology',
-          type: 'circular'
+          linkDistance: 44,
+          nodeSpacing: 10,
+          nodeStrength: -45,
+          preventOverlap: true,
+          radialRadius: 0,
+          radialStrength: 0.055,
+          type: 'd3-force'
         }),
         behaviors: expect.arrayContaining([
           expect.objectContaining({