chore: absorb the no-nudge seam into the workflow tree

The parent branch dropped structuredNudgeRetries; the two workflow-side test
setups stop passing it, and the RFC's foundation paragraph now describes the
current design (final-ASSEMBLY enforcement logged via request/header, the
post-capture pre-execute deny, the start() schema snapshot, no re-prompt)
instead of the retired agent/request + nudge shape.

packages/workflow/workflow-vm/tests/integration.spec.ts

@@ -32,7 +32,7 @@ async function setup(script: Script) {
   await ctx.plugin(Invariants)
   await ctx.plugin(AgentLoop, { agents: [] })
   await ctx.plugin(SubagentService)
-  await ctx.plugin(spawn, { providerName: 'spawn', structuredNudgeRetries: 1 })
+  await ctx.plugin(spawn, { providerName: 'spawn' })
   await ctx.plugin(VmWorkflowEngine, {})
   ctx.llm.registerAdapter(['mock'], adapter)
   const parent = ctx.agentLoop.create(AgentId('parent'), { model: 'mock' })

packages/workflow/workflow-vm/tests/workflow.e2e.ts

@@ -39,7 +39,7 @@ async function harness(): Promise<Context> {
   await built.plugin(AgentLoop, { agents: [] })
   await built.plugin(LlmDeepSeek, { models: ['deepseek-v4-flash'] })
   await built.plugin(SubagentService)
-  await built.plugin(Spawn, { providerName: 'spawn', structuredNudgeRetries: 1 })
+  await built.plugin(Spawn, { providerName: 'spawn' })
   await built.plugin(VmWorkflowEngine, { provider: 'spawn' })
   await built.plugin(ToolWorkflow, {})
   return built