feat(auth): collect the workspace logo on the sign-up creation step (#21723)

## What & why

A single, consistent **workspace-creation step** for both
multi-workspace and single-workspace self-host — collecting **name +
logo** (and the **subdomain** in multi-workspace) — which **removes the
duplicate name/logo prompt** that previously reappeared on the workspace
subdomain (reported after #21641).

## Changes

**One creation form for both modes**
- With 0 workspaces, both multi-workspace and single-workspace route to
the shared `SignInUpWorkspaceCreationForm`; `SignInUp` renders it for
the `WorkspaceCreation` step regardless of domain/scope.
- The subdomain field shows only in multi-workspace; single-workspace
keeps its fixed address.

**Logo on the creation step**
- New scoped `uploadNewWorkspaceLogo(workspaceId, file)` mutation: the
creator sets a logo on their just-created `PENDING_CREATION` workspace
via the workspace-agnostic token (membership enforced — only the creator
is a member at that point), reusing `uploadWorkspacePicture`. Upload
size is capped via `settings.storage.maxFileSize` (also applied to the
existing logo / profile-picture uploads).
- The picked file is held locally (object-URL preview, revoked on
unmount) and uploaded right after creation (non-fatal on failure).

**Onboarding step → pure activation loader**
- The old "Create your workspace" form (name + logo) is removed. The
onboarding step now activates the pending workspace on mount and shows
the loader, with a **Retry** action on failure.

## Testing
- typecheck (front + server) ✅; oxlint + oxfmt clean on changed files ✅
- Unit tests: `auth.resolver.spec`, `useWorkspaceSubdomainField`,
`SignInUpWorkspaceCreationForm` (multi + single-workspace), `useAuth` ✅
- Metadata GraphQL + `twenty-client-sdk` schema regenerated.

Follow-up to #21641.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

https://claude.ai/code/session_01Xw37hR5seiCyWnppG9z4op

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/twenty-client-sdk/src/metadata/generated/schema.graphql

@@ -3395,6 +3395,7 @@ type Mutation {
   signUp(email: String!, password: String!, captchaToken: String, locale: String, verifyEmailRedirectPath: String): AvailableWorkspacesAndAccessTokens!
   signUpInWorkspace(email: String!, password: String!, workspaceId: UUID, workspaceInviteHash: String, workspacePersonalInviteToken: String, captchaToken: String, locale: String, verifyEmailRedirectPath: String): SignUp!
   signUpInNewWorkspace(input: SignUpInNewWorkspaceInput): SignUp!
+  uploadNewWorkspaceLogo(workspaceId: String!, file: Upload!): FileWithSignedUrl!
   generateTransientToken: TransientToken!
   getAuthTokensFromLoginToken(loginToken: String!, origin: String!): AuthTokens!
   authorizeApp(clientId: String!, codeChallenge: String, redirectUrl: String!, state: String, scope: String): AuthorizeApp!
@@ -4475,6 +4476,9 @@ input UpdateWorkspaceMemberSettingsInput {
 }
 
 input ActivateWorkspaceInput {
+  """
+  Deprecated: the workspace name is set at creation (signUpInNewWorkspace) and this field is ignored during activation. Kept for backward compatibility.
+  """
   displayName: String
 }
 

packages/twenty-client-sdk/src/metadata/generated/schema.ts

@@ -2916,6 +2916,7 @@ export interface Mutation {
     signUp: AvailableWorkspacesAndAccessTokens
     signUpInWorkspace: SignUp
     signUpInNewWorkspace: SignUp
+    uploadNewWorkspaceLogo: FileWithSignedUrl
     generateTransientToken: TransientToken
     getAuthTokensFromLoginToken: AuthTokens
     authorizeApp: AuthorizeApp
@@ -6094,6 +6095,7 @@ export interface MutationGenqlSelection{
     signUp?: (AvailableWorkspacesAndAccessTokensGenqlSelection & { __args: {email: Scalars['String'], password: Scalars['String'], captchaToken?: (Scalars['String'] | null), locale?: (Scalars['String'] | null), verifyEmailRedirectPath?: (Scalars['String'] | null)} })
     signUpInWorkspace?: (SignUpGenqlSelection & { __args: {email: Scalars['String'], password: Scalars['String'], workspaceId?: (Scalars['UUID'] | null), workspaceInviteHash?: (Scalars['String'] | null), workspacePersonalInviteToken?: (Scalars['String'] | null), captchaToken?: (Scalars['String'] | null), locale?: (Scalars['String'] | null), verifyEmailRedirectPath?: (Scalars['String'] | null)} })
     signUpInNewWorkspace?: (SignUpGenqlSelection & { __args?: {input?: (SignUpInNewWorkspaceInput | null)} })
+    uploadNewWorkspaceLogo?: (FileWithSignedUrlGenqlSelection & { __args: {workspaceId: Scalars['String'], file: Scalars['Upload']} })
     generateTransientToken?: TransientTokenGenqlSelection
     getAuthTokensFromLoginToken?: (AuthTokensGenqlSelection & { __args: {loginToken: Scalars['String'], origin: Scalars['String']} })
     authorizeApp?: (AuthorizeAppGenqlSelection & { __args: {clientId: Scalars['String'], codeChallenge?: (Scalars['String'] | null), redirectUrl: Scalars['String'], state?: (Scalars['String'] | null), scope?: (Scalars['String'] | null)} })
@@ -6507,7 +6509,9 @@ export interface UpdateApplicationRegistrationVariablePayload {value?: (Scalars[
 
 export interface UpdateWorkspaceMemberSettingsInput {workspaceMemberId: Scalars['UUID'],update: Scalars['JSON']}
 
-export interface ActivateWorkspaceInput {displayName?: (Scalars['String'] | null)}
+export interface ActivateWorkspaceInput {
+/** Deprecated: the workspace name is set at creation (signUpInNewWorkspace) and this field is ignored during activation. Kept for backward compatibility. */
+displayName?: (Scalars['String'] | null)}
 
 export interface UpdateWorkspaceInput {subdomain?: (Scalars['String'] | null),customDomain?: (Scalars['String'] | null),displayName?: (Scalars['String'] | null),logo?: (Scalars['String'] | null),inviteHash?: (Scalars['String'] | null),isPublicInviteLinkEnabled?: (Scalars['Boolean'] | null),allowImpersonation?: (Scalars['Boolean'] | null),isGoogleAuthEnabled?: (Scalars['Boolean'] | null),isMicrosoftAuthEnabled?: (Scalars['Boolean'] | null),isPasswordAuthEnabled?: (Scalars['Boolean'] | null),isGoogleAuthBypassEnabled?: (Scalars['Boolean'] | null),isMicrosoftAuthBypassEnabled?: (Scalars['Boolean'] | null),isPasswordAuthBypassEnabled?: (Scalars['Boolean'] | null),defaultRoleId?: (Scalars['UUID'] | null),isTwoFactorAuthenticationEnforced?: (Scalars['Boolean'] | null),trashRetentionDays?: (Scalars['Float'] | null),eventLogRetentionDays?: (Scalars['Float'] | null),fastModel?: (Scalars['String'] | null),smartModel?: (Scalars['String'] | null),aiAdditionalInstructions?: (Scalars['String'] | null),editableProfileFields?: (Scalars['String'][] | null),enabledAiModelIds?: (Scalars['String'][] | null),useRecommendedModels?: (Scalars['Boolean'] | null),isInternalMessagesImportEnabled?: (Scalars['Boolean'] | null)}
 

packages/twenty-client-sdk/src/metadata/generated/types.ts

@@ -8454,6 +8454,19 @@ export default {
                     ]
                 }
             ],
+            "uploadNewWorkspaceLogo": [
+                131,
+                {
+                    "workspaceId": [
+                        1,
+                        "String!"
+                    ],
+                    "file": [
+                        357,
+                        "Upload!"
+                    ]
+                }
+            ],
             "generateTransientToken": [
                 250
             ],