feat(api): implement global API rate limiting for enhanced security

[MsParadox]

Pull Request: Implement Global API Rate Limiting

🎯 Overview

This PR integrates a global rate limiting architecture into the Rent-Mate backend API. By enforcing a strict request limit per IP address, this security enhancement actively protects the application against brute-force authentication attacks, potential Denial of Service (DoS) attempts, and automated database spamming.

🔗 Linked Issue

Closes #33

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🛠️ Type of Change

• Security Enhancement (Protects exposed endpoints from abuse)
• Feature (Adds @nestjs/throttler capability)

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💻 Detailed Changes

1. Dependency Integration

• Installed the official @nestjs/throttler package within the apps/api workspace.
• Updated the root package-lock.json to reflect the new monorepo dependency.

2. Module Configuration

• Imported and configured ThrottlerModule inside apps/api/src/app.module.ts.
• Established a secure baseline limit: 100 requests per 60 seconds (1 minute) per IP.

3. Global Guard Registration

• Bound the ThrottlerGuard globally using NestJS's APP_GUARD provider.
• This architectural choice ensures that all existing endpoints, as well as any future controllers added to the application, inherit this baseline protection automatically without requiring manual route-by-route decorators.

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🧪 Verification & Expected Behavior

• Normal Traffic: Standard UI and Mobile app navigation remains well under the 100 requests/minute threshold and functions transparently without interruption.
• Abuse Prevention: If a client exceeds 100 requests within a rolling 60-second window, the API immediately intercepts the request and returns an HTTP 429 Too Many Requests status code.
• Compilation: Verified the backend compiles and bootstraps successfully with the new global provider configuration.

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✅ Reviewer Checklist

• Dependencies updated correctly within the monorepo structure.
• Global guard registered accurately without accidental route bypasses.
• APP_GUARD provider order does not conflict with existing global configurations.