feat: config field in /cypher/execute — node-level component override

- /cypher/execute now accepts separate `config` field:
  {node_name: {component: "cmp_19e62efd", ...staticParams}}
- graph-builder reads config[node].component to override componentId
  (supports cmp_ hash, rec_ hash, or canonical_id)
- config[node] other fields become node.data (static params merged at runtime)
- acr run now sends workflow.config as separate `config` (not flattened into context)
- context is now only --input dynamic params

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

cli/src/commands/run.ts

@@ -64,7 +64,8 @@ export async function cmdRun(workflowName: string, options: RunOptions): Promise
         headers,
         body: JSON.stringify({
           triplets: workflow.flow,
-          context: { ...inputContext, ...(workflow.config ?? {}) },
+          config: workflow.config ?? {},   // node_name → {component, ...params}
+          context: inputContext,           // --input key=value 傳入的動態參數
           graph_id: workflow.name,
           graph_name: workflow.name,
         }),