Fix GithubCodeSearchService.triggerIndexing 401 auth error handling

[Copilot]

Fixes #318023

When the GitHub code search indexing API returns a 401, the Codebase Semantic Index spinner runs forever and never recovers—even across restarts.

Two bugs:

• codeSearchRepo.ts: if (!triggerSuccess) is always false. triggerSuccess is a Result object (always truthy). On error, the code falls through to set BuildingIndex state and return Result.ok(true), so the UI shows an infinite spinner. Fixed to triggerSuccess.isError().

• githubCodeSearchService.ts: 401/403 responses misclassified as generic-error. Both triggerIndexing and getRemoteIndexState returned { type: 'generic-error' } for all non-OK responses. The ADO equivalent already distinguishes 401/403 → { type: 'not-authorized' }. Added the same check so callers can map to the correct NotAuthorized UI state instead of CouldNotCheckIndexStatus.

[Copilot]

Pull request overview

This PR fixes Codebase Semantic Index getting stuck in an “Indexing…” spinner when GitHub’s indexing endpoints return 401/403, by correctly detecting trigger failures and classifying authorization errors so the UI can reflect an unauthenticated/unauthorized state.

Changes:

• Fix GithubCodeSearchRepo.triggerRemoteIndexingOfRepo to correctly detect Result failures (isError() vs a truthy check).
• Update GithubCodeSearchService to classify 401/403 responses as { type: 'not-authorized' } in both getRemoteIndexState and triggerIndexing.

Show a summary per file

File	Description
extensions/copilot/src/platform/workspaceChunkSearch/node/codeSearch/codeSearchRepo.ts	Fixes incorrect success detection when triggering remote indexing, preventing false “building” state.
extensions/copilot/src/platform/remoteCodeSearch/common/githubCodeSearchService.ts	Differentiates 401/403 from generic failures so callers can surface a NotAuthorized UI state.

Copilot's findings

Comments suppressed due to low confidence (1)

extensions/copilot/src/platform/workspaceChunkSearch/node/codeSearch/codeSearchRepo.ts:417

• triggerIndexing can now return { type: 'not-authorized' } (401/403), but this error path currently updates the repo state to NotYetIndexed and returns a generic request-to-index-failed error. This means the UI will keep offering “Index?” instead of the “Sign in?” / NotAuthorized state, and tryAuthIfNeeded won’t kick in because it only looks for CodeSearchRepoStatus.NotAuthorized.

		const triggerSuccess = await this._githubCodeSearchService.triggerIndexing({ silent: true }, triggerReason, this._githubRepoId, telemetryInfo);
		if (triggerSuccess.isError()) {
			this._logService.error(`RepoTracker::TriggerRemoteIndexing(${triggerReason}). Failed to request indexing for '${this.remoteInfo.repoId}'.`);

			this.updateState({ status: CodeSearchRepoStatus.NotYetIndexed });

			return Result.error(TriggerRemoteIndexingError.errorTriggeringIndexing(this.remoteInfo.repoId));

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• Comments generated: 0