chore(auth): drop unused workspacePersonalInviteToken from SSO state (#20557)

## Summary

Pure dead-code removal. The Google and Microsoft SSO strategies have
been packing `workspacePersonalInviteToken` into the OAuth `state` blob
and re-emitting it on `validate()`, but
[`signInUpWithSocialSSO`](packages/twenty-server/src/engine/core-modules/auth/services/auth.service.ts)
never destructures or reads it from the user object. The SSO flow
resolves invitations by the IdP-verified email instead:

```ts
const invitation =
  currentWorkspace && email
    ? await this.findInvitationForSignInUp({
        currentWorkspace,
        email,   // ← matched against appToken.context.email
      })
    : undefined;
```

So the strategy plumbing is write-only and confusing for readers.

Removed from:
-
[`SocialSSOState`](packages/twenty-server/src/engine/core-modules/auth/types/social-sso-state.type.ts)
- `GoogleRequest['user']` and `MicrosoftRequest['user']`
- The `state` JSON in both strategies' `authenticate()`
- The user object in both strategies' `validate()`

No frontend change needed — `useAuth.buildRedirectUrl` still sets the
`inviteToken` query param when a personal invite token is present (used
by other paths), and nothing on the SSO server side was reading it.

The token-based invitation lookup is preserved for the password signup
flow via `auth.resolver.signUp` → `findInvitationForSignInUp({
currentWorkspace, workspacePersonalInviteToken })`. Unrelated,
untouched.

## Test plan

- [x] `npx jest engine/core-modules/auth` (twenty-server) — 26 suites /
178 tests pass.
- [x] `tsgo -p tsconfig.json --noEmit` — no new errors on the touched
files (pre-existing `IS_REST_METADATA_API_NEW_FORMAT_DIRECT` errors on
main are unrelated).
- [x] `oxlint` + `prettier --check` on touched files — clean.
- [ ] Manual smoke: Google sign-in still works (workspace selection /
verify flow unaffected since `workspaceInviteHash`, `workspaceId`,
`action`, `locale`, `billingCheckoutSessionState`, `returnToPath` still
flow correctly).

packages/twenty-server/src/engine/core-modules/auth/strategies/google.auth.strategy.ts

@@ -29,7 +29,6 @@ export type GoogleRequest = Omit<
     picture: string | null;
     locale?: keyof typeof APP_LOCALES | null;
     workspaceInviteHash?: string;
-    workspacePersonalInviteToken?: string;
     action: SocialSSOSignInUpActionType;
     workspaceId?: string;
     billingCheckoutSessionState?: string;
@@ -57,7 +56,6 @@ export class GoogleStrategy extends PassportStrategy(Strategy, 'google') {
         workspaceInviteHash: req.query.workspaceInviteHash,
         workspaceId: req.params.workspaceId,
         billingCheckoutSessionState: req.query.billingCheckoutSessionState,
-        workspacePersonalInviteToken: req.query.workspacePersonalInviteToken,
         action: req.query.action,
         locale: req.query.locale,
         returnToPath: req.query.returnToPath,
@@ -94,7 +92,6 @@ export class GoogleStrategy extends PassportStrategy(Strategy, 'google') {
       lastName: name?.familyName,
       picture: photos?.[0]?.value ?? null,
       workspaceInviteHash: state?.workspaceInviteHash,
-      workspacePersonalInviteToken: state?.workspacePersonalInviteToken,
       workspaceId: state?.workspaceId,
       billingCheckoutSessionState: state?.billingCheckoutSessionState,
       action: state?.action ?? 'list-available-workspaces',

packages/twenty-server/src/engine/core-modules/auth/strategies/microsoft.auth.strategy.ts

@@ -27,7 +27,6 @@ export type MicrosoftRequest = Omit<
     picture: string | null;
     locale?: keyof typeof APP_LOCALES | null;
     workspaceInviteHash?: string;
-    workspacePersonalInviteToken?: string;
     workspaceId?: string;
     billingCheckoutSessionState?: string;
     action: SocialSSOSignInUpActionType;
@@ -57,7 +56,6 @@ export class MicrosoftStrategy extends PassportStrategy(Strategy, 'microsoft') {
         workspaceId: req.params.workspaceId,
         locale: req.query.locale,
         billingCheckoutSessionState: req.query.billingCheckoutSessionState,
-        workspacePersonalInviteToken: req.query.workspacePersonalInviteToken,
         action: req.query.action,
         returnToPath: req.query.returnToPath,
         oauthRetryCount: req.query.oauthRetryCount
@@ -92,7 +90,6 @@ export class MicrosoftStrategy extends PassportStrategy(Strategy, 'microsoft') {
       lastName: name?.familyName,
       picture: photos?.[0]?.value ?? null,
       workspaceInviteHash: state?.workspaceInviteHash,
-      workspacePersonalInviteToken: state?.workspacePersonalInviteToken,
       workspaceId: state?.workspaceId,
       billingCheckoutSessionState: state?.billingCheckoutSessionState,
       locale: state?.locale,

packages/twenty-server/src/engine/core-modules/auth/types/social-sso-state.type.ts

@@ -6,7 +6,6 @@ export type SocialSSOState = {
   workspaceInviteHash?: string;
   workspaceId?: string;
   billingCheckoutSessionState?: string;
-  workspacePersonalInviteToken?: string;
   action?: SocialSSOSignInUpActionType;
   locale?: keyof typeof APP_LOCALES;
   returnToPath?: string;