Add Activepieces integration for workflow automation

- Add Activepieces fork with SmoothSchedule custom piece
- Create integrations app with Activepieces service layer
- Add embed token endpoint for iframe integration
- Create Automations page with embedded workflow builder
- Add sidebar visibility fix for embed mode
- Add list inactive customers endpoint to Public API
- Include SmoothSchedule triggers: event created/updated/cancelled
- Include SmoothSchedule actions: create/update/cancel events, list resources/services/customers

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

activepieces-fork/packages/engine/src/lib/handler/base-executor.ts

@@ -0,0 +1,13 @@
+import { FlowAction } from '@activepieces/shared'
+import { EngineConstants } from './context/engine-constants'
+import { FlowExecutorContext } from './context/flow-execution-context'
+
+export type ActionHandler<T extends FlowAction> = (request: { action: T, executionState: FlowExecutorContext, constants: EngineConstants }) => Promise<FlowExecutorContext>
+
+export type BaseExecutor<T extends FlowAction> = {
+    handle(request: {
+        action: T
+        executionState: FlowExecutorContext
+        constants: EngineConstants
+    }): Promise<FlowExecutorContext>
+}