feat: emit metadata events for schema changes with actor context for webhooks (#17622)

## Summary

This PR adds **metadata eventing**: when schema metadata
(objectMetadata, fieldMetadata, view, viewField, etc.) is created,
updated, or deleted, we now emit events that can trigger webhooks and
future audit logs. It also adds **actor context** (`userId`,
`workspaceMemberId`) to those events so subscribers can attribute
changes to a user or API key.

## What changed

### 1. Metadata eventing (first commit)

- **MetadataEventEmitter**  
New service that emits batch events after successful workspace
migrations. Event names follow `metadata.{entity}.{action}` (e.g.
`metadata.objectMetadata.created`, `metadata.fieldMetadata.updated`).
- **MetadataEventsToDbListener**  
Listens for metadata events and enqueues webhook delivery via
`CallWebhookJobsForMetadataJob`.
- **Event types** (twenty-shared)  
`MetadataEventAction`, `MetadataEventBatch`, and record event types for
create/update/delete.
- **WorkspaceMigrationValidateBuildAndRunService**  
Calls the metadata event emitter after running migrations so all
metadata changes (from any module) emit events from a single place.
- **Create events**  
Sourced from the create action payload (`flatEntity` /
`flatFieldMetadatas`) because `fromToAllFlatEntityMaps` does not provide
a before/after diff for creates. Update/delete events still use the
fromToAllFlatEntityMaps comparison.

### 2. Actor context (second commit)

- **MetadataEventEmitter**  
Accepts optional `actorContext` (`userId`, `workspaceMemberId`) and
includes it on emitted batch events.
- **WorkspaceMigrationValidateBuildAndRunService**  
Passes `actorContext` from the request into the metadata event emitter.
- **Metadata resolvers & services**  
All metadata modules resolve `@AuthUser({ allowUndefined: true })` and
`@AuthUserWorkspaceId()` and pass `userId` and `workspaceMemberId`
through to the migration/event pipeline. Both are optional so
API-key–authenticated requests (no user) still emit events without a
user identity.
  
Shared some questions on Discord about the PR.

---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>
Co-authored-by: prastoin <paul@twenty.com>

packages/twenty-front/src/modules/settings/components/SettingsDatabaseEventsForm.tsx

@@ -1,16 +1,10 @@
-import { useObjectMetadataItems } from '@/object-metadata/hooks/useObjectMetadataItems';
+import { WebhookEntitySelect } from '@/settings/developers/components/WebhookEntitySelect';
 import { Select } from '@/ui/input/components/Select';
 import { useIsMobile } from '@/ui/utilities/responsive/hooks/useIsMobile';
 import styled from '@emotion/styled';
 import { t } from '@lingui/core/macro';
 import { isDefined } from 'twenty-shared/utils';
-import {
-  IconBox,
-  IconNorthStar,
-  IconPlus,
-  IconTrash,
-  useIcons,
-} from 'twenty-ui/display';
+import { IconBox, IconNorthStar, IconPlus, IconTrash } from 'twenty-ui/display';
 import { IconButton, type SelectOption } from 'twenty-ui/input';
 
 const OBJECT_DROPDOWN_WIDTH = 240;
@@ -51,19 +45,6 @@ export const SettingsDatabaseEventsForm = ({
 }) => {
   const isMobile = useIsMobile();
 
-  const { objectMetadataItems } = useObjectMetadataItems();
-
-  const { getIcon } = useIcons();
-
-  const objectOptions: SelectOption<string>[] = [
-    { label: t`All Objects`, value: '*', Icon: IconNorthStar },
-    ...objectMetadataItems.map((item) => ({
-      label: item.labelPlural,
-      value: item.nameSingular,
-      Icon: getIcon(item.icon),
-    })),
-  ];
-
   const getActionOptions = (
     updatedFields?: string[],
   ): SelectOption<string>[] => {
@@ -86,15 +67,12 @@ export const SettingsDatabaseEventsForm = ({
     <>
       {events.map((operation, index) => (
         <StyledFilterRow key={index} isMobile={isMobile}>
-          <Select
+          <WebhookEntitySelect
             dropdownId={`object-webhook-type-select-${index}`}
             value={operation.object}
-            options={objectOptions}
             onChange={(newValue) =>
               updateOperation?.(index, 'object', newValue)
             }
-            fullWidth
-            emptyOption={{ label: t`Object`, value: null }}
             disabled={disabled}
           />
           <Select