deprecate github.copilot extension

[sandy081]

deprecate github.copilot extension and uninstall it automatically

[Copilot]

Pull request overview

Deprecates the GitHub.copilot extension (as configured via productService.defaultChatAgent.extensionId) by marking it as non-installable and defining an auto-migration target, and adjusts uninstall behavior to avoid cascading uninstalls via extension packs.

Changes:

• Adds a hard-coded deprecation entry for the default chat agent “completions” extension, pointing to defaultChatAgent.chatExtensionId as the replacement.
• Disallows install of the deprecated extension and enables auto-migration behavior.
• Skips uninstalling extension-pack contents when uninstalling the deprecated defaultChatAgent.extensionId extension.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
src/vs/platform/extensionManagement/common/extensionGalleryService.ts	Injects a deprecation + migration mapping for defaultChatAgent.extensionId to defaultChatAgent.chatExtensionId.
src/vs/platform/extensionManagement/common/abstractExtensionManagementService.ts	Prevents uninstall from including packed extensions when uninstalling defaultChatAgent.extensionId.

[Copilot]

Setting autoMigrate here will trigger migrateUnsupportedExtensions to uninstall the deprecated extension and install the replacement, but that migration currently calls installFromGallery(..., { installPreReleaseVersion: true, ... }) unconditionally. As a result, even on stable this replacement can be marked/treated as a pre-release install (affecting update channel/metadata) regardless of the preRelease flag set here. Either adjust the migration logic to respect deprecated.extension.preRelease, or avoid using the auto-migrate path if the intent is to install the release channel on stable.

Suggested change

	deprecated[this.productService.defaultChatAgent.extensionId.toLowerCase()] = {
	disallowInstall: true,
	extension: {
	id: this.productService.defaultChatAgent.chatExtensionId,
	displayName: 'GitHub Copilot Chat',
	autoMigrate: { storage: false },
	preRelease: this.productService.quality !== 'stable'
	const isPreReleaseDefaultChatAgent = this.productService.quality !== 'stable';
	deprecated[this.productService.defaultChatAgent.extensionId.toLowerCase()] = {
	disallowInstall: true,
	extension: {
	id: this.productService.defaultChatAgent.chatExtensionId,
	displayName: 'GitHub Copilot Chat',
	...(isPreReleaseDefaultChatAgent ? { autoMigrate: { storage: false }, preRelease: true } : {})