feat: Send email from UI — inline reply composer & SendEmail mutation (#19363)

## Summary

- **Inline email reply**: Replace external email client redirects
(Gmail/Outlook deeplinks) with an in-app email composer. Users can reply
to email threads directly from the email thread widget or via the
command menu.
- **SendEmail GraphQL mutation**: New backend mutation that reuses
`EmailComposerService` for body sanitization, recipient validation, and
SMTP dispatch via the existing outbound messaging infrastructure.
- **Side panel compose page**: Command menu "Reply" action now opens a
side-panel compose email page with pre-filled To, Subject, and
In-Reply-To fields.

### Backend
- `SendEmailResolver` with `SendEmailInput` / `SendEmailOutputDTO`
- `SendEmailModule` wired into `CoreEngineModule`
- Reuses `EmailComposerService` + `MessagingMessageOutboundService`

### Frontend
- `EmailComposer` / `EmailComposerFields` components
- `useSendEmail`, `useReplyContext`, `useEmailComposerState` hooks
- `useOpenComposeEmailInSidePanel` + `SidePanelComposeEmailPage`
- `EmailThreadWidget` inline Reply bar with toggle composer
- `ReplyToEmailThreadCommand` now opens side-panel instead of external
links

### Seeds
- Added `handle` field to message participant seeds for realistic email
addresses
- Seed `connectedAccount` and `messageChannel` in correct batch order

## Test plan

- [ ] Open an email thread on a person/company record → verify
"Reply..." bar appears below the last message
- [ ] Click "Reply..." → composer opens inline with pre-filled To and
Subject
- [ ] Type a message and click Send → email is sent via SMTP, composer
closes
- [ ] Use command menu Reply action → side panel opens with compose
email page
- [ ] Verify Send/Cancel buttons work correctly in side panel
- [ ] Test with Cc/Bcc toggle in composer fields
- [ ] Verify error handling: invalid recipients, missing connected
account


Made with [Cursor](https://cursor.com)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/twenty-front/src/modules/object-record/record-show/components/PageLayoutRecordPageRenderer.tsx

@@ -10,9 +10,12 @@ import { usePageLayoutIdForRecord } from '@/page-layout/hooks/usePageLayoutIdFor
 import { LayoutRenderingProvider } from '@/ui/layout/contexts/LayoutRenderingContext';
 import { type TargetRecordIdentifier } from '@/ui/layout/contexts/TargetRecordIdentifier';
 import { SidePanelFooter } from '@/ui/layout/side-panel/components/SidePanelFooter';
+import { sidePanelWidgetFooterActionsState } from '@/ui/layout/side-panel/states/sidePanelWidgetFooterActionsState';
 import { styled } from '@linaria/react';
 import { useAtomFamilySelectorValue } from '@/ui/utilities/state/jotai/hooks/useAtomFamilySelectorValue';
+import { useAtomStateValue } from '@/ui/utilities/state/jotai/hooks/useAtomStateValue';
 import { isDefined } from 'twenty-shared/utils';
+import { Button } from 'twenty-ui/input';
 import { themeCssVariables } from 'twenty-ui/theme-constants';
 import { PageLayoutType } from '~/generated-metadata/graphql';
 
@@ -55,6 +58,16 @@ export const PageLayoutRecordPageRenderer = ({
     targetObjectNameSingular: targetRecordIdentifier.targetObjectNameSingular,
   });
 
+  const sidePanelWidgetFooterActions = useAtomStateValue(
+    sidePanelWidgetFooterActionsState,
+  );
+
+  const pinnedWidgetActions = sidePanelWidgetFooterActions.filter(
+    (action) => action.isPinned !== false,
+  );
+
+  const hasPinnedWidgetActions = pinnedWidgetActions.length > 0;
+
   return (
     <>
       <RecordShowEffect
@@ -101,13 +114,30 @@ export const PageLayoutRecordPageRenderer = ({
         {isInSidePanel && (
           <SidePanelFooter
             actions={[
-              <RecordPageSidePanelCommandMenu />,
-              <RecordShowSidePanelOpenRecordButton
-                objectNameSingular={
-                  targetRecordIdentifier.targetObjectNameSingular
-                }
-                recordId={targetRecordIdentifier.id}
-              />,
+              <RecordPageSidePanelCommandMenu key="options" />,
+              ...(hasPinnedWidgetActions
+                ? pinnedWidgetActions.map((action) => (
+                    <Button
+                      key={action.key}
+                      size="small"
+                      variant={action.isPrimaryCTA ? 'primary' : 'secondary'}
+                      accent={action.isPrimaryCTA ? 'blue' : 'default'}
+                      title={action.label}
+                      Icon={action.Icon}
+                      hotkeys={action.hotkeys}
+                      onClick={action.onClick}
+                      disabled={action.disabled}
+                    />
+                  ))
+                : [
+                    <RecordShowSidePanelOpenRecordButton
+                      key="open"
+                      objectNameSingular={
+                        targetRecordIdentifier.targetObjectNameSingular
+                      }
+                      recordId={targetRecordIdentifier.id}
+                    />,
+                  ]),
             ]}
           />
         )}