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/side-panel/components/SidePanelRecordInfo.tsx

@@ -14,14 +14,28 @@ import { RecordTitleCellContainerType } from '@/object-record/record-title-cell/
 import { useAtomComponentStateValue } from '@/ui/utilities/state/jotai/hooks/useAtomComponentStateValue';
 import { Trans } from '@lingui/react/macro';
 import { isNonEmptyString } from '@sniptt/guards';
+import { styled } from '@linaria/react';
 import { useAtomFamilySelectorValue } from '@/ui/utilities/state/jotai/hooks/useAtomFamilySelectorValue';
 import { useAtomStateValue } from '@/ui/utilities/state/jotai/hooks/useAtomStateValue';
+import { AppPath } from 'twenty-shared/types';
+import { getAppPath } from 'twenty-shared/utils';
 import { Avatar } from 'twenty-ui/display';
+import { UndecoratedLink } from 'twenty-ui/navigation';
 import { FieldMetadataType } from '~/generated-metadata/graphql';
 import { dateLocaleState } from '~/localization/states/dateLocaleState';
+
 import { beautifyPastDateRelativeToNow } from '~/utils/date-utils';
 import { SidePanelPageInfoLayout } from './SidePanelPageInfoLayout';
 
+const StyledClickableTitle = styled.div`
+  cursor: pointer;
+
+  a {
+    color: inherit;
+    text-decoration: none;
+  }
+`;
+
 export const SidePanelRecordInfo = ({
   sidePanelPageInstanceId,
 }: {
@@ -85,6 +99,11 @@ export const SidePanelRecordInfo = ({
     objectNameSingular,
   });
 
+  const recordShowPagePath = getAppPath(AppPath.RecordShowPage, {
+    objectNameSingular,
+    objectRecordId,
+  });
+
   const fieldDefinition = {
     type: labelIdentifierFieldMetadataItem?.type ?? FieldMetadataType.TEXT,
     iconName: '',
@@ -97,6 +116,25 @@ export const SidePanelRecordInfo = ({
     defaultValue: labelIdentifierFieldMetadataItem?.defaultValue,
   };
 
+  const titleContent = (
+    <FieldContext.Provider
+      value={{
+        recordId: objectRecordId,
+        isLabelIdentifier: false,
+        fieldDefinition,
+        useUpdateRecord: useUpdateOneObjectRecordMutation,
+        isCentered: false,
+        isDisplayModeFixHeight: true,
+        isRecordFieldReadOnly: isTitleReadOnly,
+      }}
+    >
+      <RecordTitleCell
+        sizeVariant="sm"
+        containerType={RecordTitleCellContainerType.PageHeader}
+      />
+    </FieldContext.Provider>
+  );
+
   return (
     <SidePanelPageInfoLayout
       icon={
@@ -111,22 +149,15 @@ export const SidePanelRecordInfo = ({
         ) : undefined
       }
       title={
-        <FieldContext.Provider
-          value={{
-            recordId: objectRecordId,
-            isLabelIdentifier: false,
-            fieldDefinition,
-            useUpdateRecord: useUpdateOneObjectRecordMutation,
-            isCentered: false,
-            isDisplayModeFixHeight: true,
-            isRecordFieldReadOnly: isTitleReadOnly,
-          }}
-        >
-          <RecordTitleCell
-            sizeVariant="sm"
-            containerType={RecordTitleCellContainerType.PageHeader}
-          />
-        </FieldContext.Provider>
+        isTitleReadOnly ? (
+          <StyledClickableTitle>
+            <UndecoratedLink to={recordShowPagePath}>
+              {titleContent}
+            </UndecoratedLink>
+          </StyledClickableTitle>
+        ) : (
+          titleContent
+        )
       }
       label={
         beautifiedCreatedAt ? (