Add support for GH Custom Agents

[pwang347]

Related: microsoft/vscode#278251

[Copilot]

Pull request overview

This pull request adds support for GitHub Custom Agents from GitHub Enterprise and Organizations. It introduces infrastructure to fetch, cache, and provide custom agent resources (.agent.md files) from organization and enterprise-level GitHub repositories, making them available as chat participants in VS Code. The implementation includes a new provider that integrates with the VS Code proposed API for custom agents, a new GitHub API endpoint for fetching agent details, and a configuration setting to enable/disable this feature.

Key changes:

• New getCustomAgentDetails API method to fetch full agent configurations including prompts
• OrganizationAndEnterpriseAgentProvider that implements caching and provides agents to VS Code
• Configuration setting chat.customAgents.showOrganizationAndEnterpriseAgents to control feature availability

Reviewed changes

Copilot reviewed 8 out of 10 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/platform/github/common/githubService.ts	Adds interface definitions for custom agent details and list options, plus method signature for fetching agent details
src/platform/github/common/octoKitServiceImpl.ts	Implements getCustomAgentDetails method to fetch full agent configuration from GitHub API
src/platform/configuration/common/configurationService.ts	Adds configuration key for enabling organization/enterprise agents
src/extension/vscode.proposed.chatParticipantPrivate.d.ts	Adds VS Code API type definitions for CustomAgentsProvider, CustomAgentResource, and related interfaces
src/extension/extension/vscode-node/contributions.ts	Registers the new OrganizationAndEnterpriseAgentContribution
src/extension/agents/vscode-node/organizationAndEnterpriseAgentProvider.ts	Core provider implementation that fetches agents from GitHub, caches them locally, and provides them to VS Code
src/extension/agents/vscode-node/organizationAndEnterpriseAgentContrib.ts	Contribution class that conditionally registers the provider based on configuration
package.nls.json	Adds localization string for the new configuration setting
package.json	Adds configuration schema and updates @vscode/copilot-api dependency to 0.2.5
package-lock.json	Updates lock file for new @vscode/copilot-api version

Comments suppressed due to low confidence (1)

src/platform/github/common/githubService.ts:152

• The CustomAgentListOptions interface is defined twice (lines 140-145 and 147-152) with identical content. Remove the duplicate definition.

export interface CustomAgentListOptions {
	target?: 'github-copilot' | 'vscode';
	excludeInvalidConfig?: boolean;
	dedupe?: boolean;
	includeSources?: ('repo' | 'org' | 'enterprise')[];
}