fix(FN-2650): align dashboard createFnAgent aliases with static engine import

- Replace namespace engine imports with a named createFnAgent import in planning and chat modules
- Alias imported createFnAgent to engineCreateFnAgent and wire local createFnAgent binding to it
- Preserve existing injectable createFnAgent variable pattern while avoiding dynamic namespace access pitfalls

packages/dashboard/src/planning.ts

@@ -30,12 +30,12 @@ import {
   resetDiagnosticsSink,
   nonfatal,
 } from "./ai-session-diagnostics.js";
-import * as engine from "@fusion/engine";
+import { createFnAgent as engineCreateFnAgent } from "@fusion/engine";
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 type AgentResult = any;
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-let createFnAgent: any = engine.createFnAgent;
+let createFnAgent: any = engineCreateFnAgent;
 
 interface PlanningNtfyConfig {
   enabled: boolean;