Issue 51 pcu group methods

[bdunn313]

Summary

Adds two missing PCU endpoints to the OpenAPI spec and regenerates the Go client.

New endpoints

• POST /v2/pcus/types (pcuGetTypes): Returns available PCU types, accepting optional
  region/provider filters via PCUGroupTypesRequest body. Response is an array of PCUGroupTypeResponse.
• GET /v2/pcus/actions/get/{datacenterUUID} (pcuGroupGetByDatacenterUUID): Returns the PCU
  group for a given datacenter UUID. Response is an array of PCUGroup.

Both endpoints are tagged PCU and match the upstream public spec.

New schemas

Schema	Description
PCUGroupTypesRequest	Request body for pcuGetTypes — optional provider and region filters
PCUGroupTypeResponse	Single item in the pcuGetTypes response
PCUGroupTypeDetails	Nested hardware details within PCUGroupTypeResponse (vCPU, memory, disk cache)
PCUGroupType	String discriminator for PCU type

Response code format

New PCU endpoints use literal '500' / '400' response codes as required by oapi-codegen.

---

Usage examples

List PCU types (all providers/regions)

client, _ := astra.NewClientWithResponses("https://api.astra.datastax.com")

resp, err := client.PcuGetTypesWithResponse(ctx, astra.PCUGroupTypesRequest{})
if err != nil {
    return err
}
for _, t := range *resp.JSON200 {
    fmt.Printf("type=%s provider=%s region=%s vCPU=%d\n",
        *t.Type, *t.Provider, *t.Region, *t.Details.VCPU)
}

List PCU types filtered by provider and region

provider := "AWS"
region   := "us-east-1"

resp, err := client.PcuGetTypesWithResponse(ctx, astra.PCUGroupTypesRequest{
    Provider: &provider,
    Region:   &region,
})
if err != nil {
    return err
}
// resp.JSON200 is *[]astra.PCUGroupTypeResponse

Get PCU group for a datacenter

resp, err := client.PcuGroupGetByDatacenterUUIDWithResponse(ctx, datacenterUUID)
if err != nil {
    return err
}
for _, g := range *resp.JSON200 {
    fmt.Printf("uuid=%s region=%s status=%s\n", *g.Uuid, *g.Region, *g.Status)
}

---

Checklist

• make generate passes cleanly
• make build compiles cleanly
• No existing operationId or schema field changed (backward-compatible)
• All new fields sourced from upstream public spec — no invented fields

Closes #51

[toptobes]

Looks good to me. It's strange that pcuGroupGetByDatacenterUUID returns an array but it seems to be for backwards compatibility from the API so we probably shouldn't do anything about it here since it's just an autogenerated wrapper