Support sender variable on workflow send-email action (#22512)

## Context

Draft-email workflow steps already accept a workspace member variable as
the sender: the step input's `connectedAccountId` can hold a workflow
variable that resolves to a workspace member id, which the action then
maps to that member's first connected account. Send-email steps were
gated out of this and only accepted a static connected account pick.

This enables the same dynamic sender resolution on send-email, e.g.
sending from the assignee/owner of the record that triggered the
workflow.

## What changed

- Removed the draft-only gate in
`EmailWorkflowActionBase.postprocessInput` so send-email resolves a
workspace member id to a connected account the same way draft-email does
- Exposed the variable picker and hint on the Account field for both
email actions in the workflow step editor
- Updated the send-email action spec to cover sender resolution (mirrors
the draft-email spec) and replaced the `SendEmailHasNoVariablePicker`
story with a variable-sender story for `SEND_EMAIL`

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packages/twenty-front/src/modules/workflow/workflow-steps/workflow-actions/components/WorkflowEditActionEmailBase.tsx

@@ -121,9 +121,6 @@ export const WorkflowEditActionEmailBase = ({
   const { accounts: myAccounts, loading: myAccountsLoading } =
     useMyConnectedAccounts();
 
-  // Sender variables are only enabled for DRAFT_EMAIL for now; SEND_EMAIL keeps a plain account select.
-  const isSenderVariableEnabled = action.type === 'DRAFT_EMAIL';
-
   const configuredAccountId = formData.connectedAccountId;
   const isSenderVariable = isStandaloneVariableString(configuredAccountId);
   const isConfiguredAccountMine = myAccounts.some(
@@ -205,17 +202,11 @@ export const WorkflowEditActionEmailBase = ({
           <FormSelectFieldInput
             key={`connected-account-${formData.connectedAccountId ?? 'none'}`}
             label={t`Account`}
-            hint={
-              isSenderVariableEnabled
-                ? t`Pick a connected account or set a workspace member as variable`
-                : undefined
-            }
+            hint={t`Pick a connected account or set a workspace member as variable`}
             defaultValue={formData.connectedAccountId}
             options={connectedAccountOptions}
             onChange={handleConnectedAccountChange}
-            VariablePicker={
-              isSenderVariableEnabled ? WorkflowVariablePicker : undefined
-            }
+            VariablePicker={WorkflowVariablePicker}
             readonly={actionOptions.readonly}
             callToActionButton={{
               onClick: () => {

packages/twenty-front/src/modules/workflow/workflow-steps/workflow-actions/components/__stories__/WorkflowEditActionEmailBase.stories.tsx

@@ -128,6 +128,36 @@ const DEFAULT_DRAFT_EMAIL_ACTION: WorkflowDraftEmailAction = {
   },
 };
 
+const VARIABLE_SENDER_SEND_EMAIL_ACTION: WorkflowSendEmailAction = {
+  id: getWorkflowNodeIdMock(),
+  name: 'Send Email',
+  type: 'SEND_EMAIL',
+  valid: true,
+  settings: {
+    input: {
+      connectedAccountId: '{{trigger._metadata.workspaceMemberId}}',
+      recipients: {
+        to: 'test@twenty.com',
+        cc: '',
+        bcc: '',
+      },
+      subject: 'Welcome to Twenty!',
+      body: 'Hello',
+      files: [],
+      inReplyTo: '',
+    },
+    outputSchema: {},
+    errorHandlingOptions: {
+      retryOnFailure: {
+        value: false,
+      },
+      continueOnFailure: {
+        value: false,
+      },
+    },
+  },
+};
+
 const VARIABLE_SENDER_DRAFT_EMAIL_ACTION: WorkflowDraftEmailAction = {
   id: getWorkflowNodeIdMock(),
   name: 'Draft Email',
@@ -283,11 +313,9 @@ export const VariableSender: Story = {
   },
 };
 
-// SEND_EMAIL does not expose the sender variable picker yet (DRAFT_EMAIL only),
-// so the account field stays a plain select with no variable hint.
-export const SendEmailHasNoVariablePicker: Story = {
+export const VariableSenderSendEmail: Story = {
   args: {
-    action: DEFAULT_SEND_EMAIL_ACTION,
+    action: VARIABLE_SENDER_SEND_EMAIL_ACTION,
     actionOptions: {
       onActionUpdate: fn(),
     },
@@ -296,10 +324,11 @@ export const SendEmailHasNoVariablePicker: Story = {
     const canvas = within(canvasElement);
 
     expect(await canvas.findByText('Account')).toBeVisible();
+    expect(await canvas.findByLabelText('Remove variable')).toBeInTheDocument();
     expect(
-      canvas.queryByText(
+      await canvas.findByText(
         'Pick a connected account or set a workspace member as variable',
       ),
-    ).not.toBeInTheDocument();
+    ).toBeVisible();
   },
 };