fix(FN-2055): harden node test utilities and import resolution

- Convert seed-sample-nodes into a test-only helper and remove direct execution against the real central database
- Replace private-looking host examples with RFC 5737 test-net addresses in node connection docs and ConnectNodeModal expectations
- Add Vitest aliases for @fusion/core and @fusion/engine to stabilize cross-package test imports
- Load AgentReflectionService via local engine source path in in-process runtime to avoid alias resolution failures

packages/engine/src/runtimes/in-process-runtime.ts

@@ -292,10 +292,10 @@ export class InProcessRuntime
       }
 
       // 5c. Initialize AgentReflectionService (requires agentStore and reflectionStore)
-      let reflectionService: import("@fusion/engine").AgentReflectionService | undefined;
+      let reflectionService: import("../agent-reflection.js").AgentReflectionService | undefined;
       if (agentStoreForReflection && reflectionStoreForService) {
         try {
-          const { AgentReflectionService: AgentReflectionServiceClass } = await import("@fusion/engine");
+          const { AgentReflectionService: AgentReflectionServiceClass } = await import("../agent-reflection.js");
           reflectionService = new AgentReflectionServiceClass({
             agentStore: agentStoreForReflection,
             taskStore: this.taskStore,