upcoming: [M3-9511] - VPC IPv6 - Update endpoints and types for VPC Entity (#11852)

## Description 📝
Update endpoints and types for VPC Entity

## Changes  🔄
- Add optional `ipv6` property to `VPC` and `CreateVPCPayload` interface
- Add optional `ipv6` validation to `createVPCSchema`

### Verification steps

(How to verify changes)

- [ ] Cross-reference VPC IPv6 API spec (linked in parent ticket) and updated types for 
POST /v4/vpcs
GET /v4/vpcs
GET /v4/vpcs/{vpcId}

Author: hana-akamai

packages/api-v4/.changeset/pr-11852-upcoming-features-1742414634244.md

@@ -0,0 +1,5 @@
+---
+"@linode/api-v4": Upcoming Features
+---
+
+Added optional ipv6 property to VPC entity ([#11852](https://github.com/linode/manager/pull/11852))

packages/api-v4/src/vpcs/types.ts

@@ -1,3 +1,11 @@
+interface VPCIPv6 {
+  range?: string;
+}
+
+interface CreateVPCIPV6 extends VPCIPv6 {
+  allocation_class?: string;
+}
+
 export interface VPC {
   id: number;
   label: string;
@@ -6,12 +14,14 @@ export interface VPC {
   subnets: Subnet[];
   created: string;
   updated: string;
+  ipv6?: VPCIPv6[];
 }
 
 export interface CreateVPCPayload {
   label: string;
   description?: string;
   region: string;
+  ipv6?: CreateVPCIPV6[];
   subnets?: CreateSubnetPayload[];
 }
 

packages/validation/.changeset/pr-11852-upcoming-features-1742414737915.md

@@ -0,0 +1,5 @@
+---
+"@linode/validation": Upcoming Features
+---
+
+Added optional ipv6 to `createVPCIPv6Schema` ([#11852](https://github.com/linode/manager/pull/11852))

packages/validation/src/vpcs.schema.ts

@@ -94,6 +94,10 @@ export const vpcsValidateIP = ({
     }
 
     if (isIPv6) {
+      // VPCs must be assigned an IPv6 prefix of /52, /48, or /44
+      if (!['52', '48', '44'].includes(mask)) {
+        return false;
+      }
       if (shouldHaveIPMask) {
         ipaddr.IPv6.parseCIDR(value);
       } else {
@@ -210,11 +214,31 @@ export const createSubnetSchema = object().shape(
   ]
 );
 
+const createVPCIPv6Schema = object({
+  range: string()
+    .optional()
+    .test({
+      name: 'IPv6 prefix length',
+      message: 'Must be the prefix length 52, 48, or 44 of the IP, e.g. /52',
+      test: (value) => {
+        if (value && value !== 'auto' && value.length > 0) {
+          vpcsValidateIP({
+            value,
+            shouldHaveIPMask: true,
+            mustBeIPMask: false,
+          });
+        }
+      },
+    }),
+  allocation_class: string().optional(),
+});
+
 export const createVPCSchema = object({
   label: labelValidation.required(LABEL_REQUIRED),
   description: string(),
   region: string().required('Region is required'),
   subnets: array().of(createSubnetSchema),
+  ipv6: array().of(createVPCIPv6Schema).max(1).optional(),
 });
 
 export const modifySubnetSchema = object({