upcoming: [M3-10125] - Add feature flag support for Cloud NAT (linode#12388)

## Description 📝

Add feature flag support for Cloud NAT

## How to test 🧪

### Verification steps

(How to verify changes)

- [ ] Checkout this PR or PR preview link
- [ ] Verify Cloud NAT is present in the Dev Tools Feature Flags section
- [ ] Verify Cloud NAT in the LD response

Author: hana-akamai

packages/manager/.changeset/pr-12388-upcoming-features-1750093823194.md

@@ -0,0 +1,5 @@
+---
+"@linode/manager": Upcoming Features
+---
+
+Add feature flag support for Cloud NAT ([#12388](https://github.com/linode/manager/pull/12388))

packages/manager/src/dev-tools/FeatureFlagTool.tsx

@@ -26,6 +26,7 @@ const options: { flag: keyof Flags; label: string }[] = [
   { flag: 'apl', label: 'Akamai App Platform' },
   { flag: 'aplGeneralAvailability', label: 'Akamai App Platform GA' },
   { flag: 'blockStorageEncryption', label: 'Block Storage Encryption (BSE)' },
+  { flag: 'cloudNat', label: 'Cloud NAT' },
   { flag: 'disableLargestGbPlans', label: 'Disable Largest GB Plans' },
   { flag: 'gecko2', label: 'Gecko' },
   { flag: 'limitsEvolution', label: 'Limits Evolution' },

packages/manager/src/featureFlags.ts

@@ -70,6 +70,11 @@ interface LkeEnterpriseFlag extends BaseFeatureFlag {
   la: boolean;
 }
 
+interface CloudNatFlag extends BetaFeatureFlag {
+  ga: boolean;
+  la: boolean;
+}
+
 export interface CloudPulseResourceTypeMapFlag {
   dimensionKey: string;
   maxResourceSelections?: number;
@@ -126,6 +131,7 @@ export interface Flags {
   aplGeneralAvailability: boolean;
   blockStorageEncryption: boolean;
   cloudManagerDesignUpdatesBanner: DesignUpdatesBannerFlag;
+  cloudNat: CloudNatFlag;
   databaseAdvancedConfig: boolean;
   databaseBeta: boolean;
   databaseResize: boolean;