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/shared/src/lib/engine/index.ts

@@ -0,0 +1,11 @@
+export * from './engine-operation'
+export * from './requests'
+export * from './engine-constants'
+export * from './execution-errors'
+
+export enum ExecutionMode {
+    SANDBOX_PROCESS = 'SANDBOX_PROCESS',
+    SANDBOX_CODE_ONLY = 'SANDBOX_CODE_ONLY',
+    UNSANDBOXED = 'UNSANDBOXED',
+    SANDBOX_CODE_AND_PROCESS = 'SANDBOX_CODE_AND_PROCESS',
+}