Feature: Introduce Organizer-Level Webhooks for Event Lifecycle Management ( #1047 )

[Sipioteo]

Summary

This PR introduces Organizer-level webhook support, allowing external systems to react to organizer-wide lifecycle events (such as event creation, updates, and archival).

Previously, webhooks were strictly per-event. While great for granular control, this made centralized integrations and multi-tenant scaling difficult for organizers managing numerous events. This update enhances flexibility by allowing webhooks to be associated with either specific events or at the top-level Organizer.

Problem / Motivation

In Hi.Events, an Organizer (Organization) is the top-level entity. When webhooks are only configured per-event, integrations become hard to scale and maintain. This PR allows defining webhooks at the Organizer level, enabling:

1. Central Integrations: Org admins can listen to event.created to provision resources in external systems (CRM, ticketing, analytics) or start automations.
2. Automatic Provisioning: External endpoints can receive organizer-level events and automatically call back Hi.Events to attach specific event-level hooks to newly created events.
3. Governance & Safety: Independent webhook configurations, secrets, and permissions per organizer with strict boundaries and no cross-org leakage.

Technical Changes

• Organizer Webhook Support: Added new actions (CreateOrganizerWebhookAction, EditOrganizerWebhookAction, DeleteOrganizerWebhookAction, etc.) and established proper relationships in the Organizer and Webhook models.
• Webhook Handler Enhancements: Modified webhook handler DTOs and core logic to accept an optional organizerId. This securely separates event-level and organizer-level contexts.
• Event Webhook Dispatching: Introduced DispatchEventWebhookJob to handle asynchronous webhook dispatching when events are created, updated, or archived (via CreateEventHandler, UpdateEventHandler, UpdateEventStatusHandler).

Checklist

• I have read the contributing guidelines.
• My code is of good quality and follows the coding standards of the project.
• I have tested my changes, and they work as expected.

Resolutions

This PR resolves #1047

[Sipioteo]

[daveearley]

Thanks for this! Awesome work. I'll test this shortly

[daveearley]

Looks good! I pushed a few minor changes.

Thanks again.