feat: engine injects extract provider at runtime (Phase 2)

- createWorkflow(def, binding) — no more extract/llmProvider params
- Engine resolves extract provider from workflow.yaml via resolveModel
- WorkflowFnOptions now carries extract + llmProvider (engine-injected)
- Delete extract-provider.ts, inline maxDepth helper
- Template packages simplified: only take agent binding
- Breaking change: bundles no longer carry provider config

Refs #110

packages/workflow-template-develop/src/index.ts

@@ -1,8 +1,6 @@
 import {
   type AgentBinding,
   createWorkflow,
-  type ExtractFn,
-  type LlmProvider,
   type WorkflowDefinition,
   type WorkflowFn,
 } from "@uncaged/workflow";
@@ -43,10 +41,6 @@ export const developWorkflowDefinition: WorkflowDefinition<DevelopMeta> = {
   moderator: developModerator,
 };
 
-export function createDevelopRun(
-  binding: AgentBinding,
-  extract: ExtractFn,
-  llmProvider: LlmProvider | null,
-): WorkflowFn {
-  return createWorkflow(developWorkflowDefinition, binding, extract, llmProvider);
+export function createDevelopRun(binding: AgentBinding): WorkflowFn {
+  return createWorkflow(developWorkflowDefinition, binding);
 }