Fix ES module bundling issues by isolating pure types

- Create dedicated types-only module (src/types/index.ts) with pure type definitions
- Update main index.ts to export only pure types without runtime imports
- Removes need for serverExternalPackages in Next.js configuration
- Plugin now works "out of the box" without bundling workarounds

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/types/index.ts

@@ -0,0 +1,62 @@
+// Pure type definitions for client-safe exports
+// This file contains NO runtime code and can be safely bundled
+
+export interface CustomTriggerOptions {
+  workflowId: string
+  triggerData?: any
+  req?: any // PayloadRequest type, but avoiding import to keep this client-safe
+}
+
+export interface TriggerResult {
+  success: boolean
+  runId?: string
+  error?: string
+}
+
+export interface ExecutionContext {
+  trigger: {
+    type: string
+    doc?: any
+    data?: any
+  }
+  steps: Record<string, {
+    output?: any
+    state: 'pending' | 'running' | 'succeeded' | 'failed'
+  }>
+  payload: any // Payload instance
+  req: any // PayloadRequest
+}
+
+export interface WorkflowStep {
+  id: string
+  type: string
+  input: Record<string, any>
+  dependencies?: string[]
+}
+
+export interface WorkflowTrigger {
+  type: 'collection' | 'global' | 'webhook' | 'cron' | 'manual'
+  collection?: string
+  global?: string
+  event?: 'create' | 'update' | 'delete' | 'read'
+  path?: string
+  cron?: string
+}
+
+export interface Workflow {
+  id: string
+  name: string
+  description?: string
+  active: boolean
+  triggers: WorkflowTrigger[]
+  steps: WorkflowStep[]
+}
+
+export interface WorkflowsPluginConfig {
+  collections?: string[]
+  globals?: string[]
+  logging?: {
+    level?: 'debug' | 'info' | 'warn' | 'error'
+    enabled?: boolean
+  }
+}