[FIX_TYPECHECK_ON_MAIN] Add missing inviteTeamMaxCreditsReward to OnboardingConfig type (#22370)

## Context

The `twenty-front` typecheck is broken on `main`:

```
src/modules/onboarding/hooks/useInviteTeam.ts:154:27 - error TS2551: Property 'inviteTeamMaxCreditsReward' does not exist on type 'OnboardingConfig'.
```

This is a merge race: one PR started consuming
`onboardingConfig.inviteTeamMaxCreditsReward` in `useInviteTeam.ts`,
while the frontend `OnboardingConfig` type only declared
`inviteTeamCreditsRewardPerUser`. The backend already returns both
fields (`client-config.entity.ts` declares `inviteTeamMaxCreditsReward`
and the service populates it), so this is purely a missing frontend type
field.

## Changes

- Add `inviteTeamMaxCreditsReward: number` to the frontend
`OnboardingConfig` type.
- Add the field to the config mock so `mock-data/config.ts` satisfies
the type.

## Test

`npx nx typecheck twenty-front` passes.

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packages/twenty-front/src/modules/client-config/types/OnboardingConfig.ts

@@ -1,5 +1,6 @@
 export type OnboardingConfig = {
   importContactsCreditsReward: number;
+  inviteTeamMaxCreditsReward: number;
   inviteTeamCreditsRewardPerUser: number;
   upgradeCreditsReward: number;
 };

packages/twenty-front/src/testing/mock-data/config.ts

@@ -46,6 +46,7 @@ export const mockedClientConfig: ClientConfig = {
   api: { mutationMaximumAffectedRecords: 100 },
   onboarding: {
     importContactsCreditsReward: 2,
+    inviteTeamMaxCreditsReward: 9,
     inviteTeamCreditsRewardPerUser: 3,
     upgradeCreditsReward: 5,
   },