Add tenant resource limit enforcement in API request handlers

[RUKAYAT-CODER]

Overview

src/tenancy/entities/tenant.entity.ts stores userLimit and storageLimit but there is no enforcement of these limits in API handlers. A tenant can create unlimited users or upload unlimited content, violating billing agreements.

Specifications

Features:

• Enforce userLimit on user creation for a tenant.
• Enforce storageLimit on content upload for a tenant.

Tasks:

• Create TenantLimitGuard that injects TenancyService and checks the relevant limit before allowing the operation.
• Apply the guard to user-creation and content-upload endpoints.
• Return 402 Payment Required when limit is exceeded.
• Add unit tests for at-limit and over-limit scenarios.

Impacted Files:

• New src/tenancy/guards/tenant-limit.guard.ts
• User creation and CDN upload controllers.

Acceptance Criteria

• User creation beyond userLimit returns 402.
• Storage upload beyond storageLimit returns 402.
• Tenants at exactly the limit can still create one more (boundary condition tested).

[sudo-robi]

@sudo-robi has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer I'm a full stack developer and smart contract developer let me help you resolve this issue and I assure you it will be thoroughly done neatly as I have seen my way to solve the issue.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @sudo-robi to this issue.

[aliyuHabibu]

@aliyuHabibu has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi please assign this issue to me. Thank you

ℹ️ Repo Maintainers: To accept this application, review their application or assign @aliyuHabibu to this issue.

[sudo-robi]

Hi @RUKAYAT-CODER please assign me this issue as the wave is about to end.