fix(dashboard): feedback edges connect from node sides via left/right handles (#247)

What: Feedback (back) edges now connect from the left/right side of nodes
instead of top/bottom, making the routing visually clearer.

Changes:
- role-node.tsx: add Left/Right handles for feedback edge connections
- use-layout.ts: set sourceHandle/targetHandle for feedback edges
- condition-edge.tsx + use-layout.ts: increase FEEDBACK_OFFSET_X to 140

Ref: #247

packages/workflow-dashboard/src/components/workflow-graph/role-node.tsx

@@ -46,6 +46,10 @@ export function RoleNode(props: NodeProps) {
       title={data.description}
     >
       <Handle type="target" position={Position.Top} style={handleStyle} isConnectable={false} />
+      <Handle type="target" position={Position.Left} id="left-in" style={handleStyle} isConnectable={false} />
+      <Handle type="target" position={Position.Right} id="right-in" style={handleStyle} isConnectable={false} />
+      <Handle type="source" position={Position.Left} id="left-out" style={handleStyle} isConnectable={false} />
+      <Handle type="source" position={Position.Right} id="right-out" style={handleStyle} isConnectable={false} />
       <div className="flex items-center gap-1.5 font-mono">
         {icon !== null && (
           <span

packages/workflow-dashboard/src/components/workflow-graph/use-layout.ts

@@ -216,6 +216,8 @@ function computeLayout(input: LayoutInput): LayoutResult {
       id: edgeKey(e),
       source: e.from,
       target: e.to,
+      sourceHandle: isFeedback ? (feedbackSide === "left" ? "left-out" : "right-out") : undefined,
+      targetHandle: isFeedback ? (feedbackSide === "left" ? "left-in" : "right-in") : undefined,
       type: "condition",
       data: {
         condition: e.condition,