Add support for reading issue field values - #14130

api/issue_fields.go:27

• 🛑 Requirement: Enable the Issue Fields GraphQL preview for field discovery

This repository-field query also uses the public-preview schema, but the shared API client currently sends only the merge_queue GraphQL feature (api/client.go:23,59). Without GraphQL-Features: issue_fields, gh issue field list will fail against the live API even though the mocked response succeeds. Add the preview feature to the shared GraphQL header and assert it in the request test.

	query RepositoryIssueFields($owner: String!, $name: String!, $endCursor: String) {
		repository(owner: $owner, name: $name) {
			issueFields(first: 100, after: $endCursor) {

internal/featuredetection/feature_detection.go:209

• 🛑 Requirement: Keep issue feature detection to one API round trip

Every GHES call to IssueFeatures now launches a second introspection request, affecting unrelated existing flows such as issue create/edit and PR create. This violates the repository's “avoid extra round-trips” API rule and makes those commands fail if either request fails. Add the two aliased __type selections to the existing featureDetection struct and resolve all flags from one Query call instead.

	wg.Go(func() error {
		return gql.Query(d.host, "Issue_fields", &featureDetection, nil)
	})
	wg.Go(func() error {
		return gql.Query(d.host, "Issue_field_types", &issueFieldFeatureDetection, nil)

pkg/cmd/issue/view/view.go:140

• 💭 Commentary: Avoid fetching values that the non-TTY renderer discards

This branch runs for both TTY and redirected output, but printRawIssuePreview never emits issue fields. As a result, scripted/default non-TTY views request up to 100 extra values and take on another API failure mode without any user-visible result. Gate this lookup on IsStdoutTTY() (or deliberately add a documented raw-output contract, which would be breaking).

			if issueFeatures.IssueFieldsSupported {

pkg/cmd/issue/view/view.go:136

• 🛑 Requirement: Keep the cleanup marker directly above the feature-gated branch

The repository feature-detection convention requires the cleanup TODO immediately above the if that tests the capability (AGENTS.md:161-172). This refactor leaves IssueRelationshipsCleanup above the detector call instead, so move it onto this branch.

			if issueFeatures.IssueRelationshipsSupported {

internal/featuredetection/feature_detection.go:208

• 🛑 Requirement: Fold these type checks into the existing introspection request

Every IssueFeatures call on GHES now makes two HTTP requests, including commands such as issue/PR create and edit that already depend on this detector. This violates the repository's “Avoid extra round-trips” API rule (AGENTS.md:176-186). Add these two aliased __type selections to featureDetection and run one gql.Query instead; concurrency only hides latency and does not remove the extra server/cache load.

	var wg errgroup.Group
	wg.Go(func() error {
		return gql.Query(d.host, "Issue_fields", &featureDetection, nil)
	})
	wg.Go(func() error {