fix session types when switching workspaces

[sandy081]

No description provided.

[Copilot]

Pull request overview

This PR addresses incorrect/invalid session-type behavior when switching workspaces in the Agents/Sessions chat UI by ensuring session type options are derived from the newly selected workspace and by correctly identifying Copilot Cloud sessions when getSessionTypes is invoked with a session-resource URI.

Changes:

• Update Copilot provider getSessionTypes to treat Copilot Cloud session-resource URI schemes as Cloud-only.
• When switching workspaces in the New Chat view, validate the currently selected session type against the new workspace’s supported session types before creating the new session.

Show a summary per file

File	Description
src/vs/sessions/contrib/copilotChatSessions/browser/copilotChatSessionsProvider.ts	Fixes Cloud session-type detection when getSessionTypes is called with a Copilot Cloud session URI scheme.
src/vs/sessions/contrib/chat/browser/newChatViewPane.ts	Validates/picks a supported session type on workspace switch before calling _onWorkspaceSelected.

Copilot's findings

Comments suppressed due to low confidence (1)

src/vs/sessions/contrib/copilotChatSessions/browser/copilotChatSessionsProvider.ts:1291

• getSessionTypes now has special handling for workspaceUri.scheme === SessionType.CopilotCloud (i.e. when called with a session resource URI), but the existing unit tests only cover file and github-remote-file schemes. Add a test case that passes a URI with the Copilot Cloud session scheme (e.g. URI.from({ scheme: AgentSessionProviders.Cloud, ... })) and asserts only CopilotCloudSessionType is returned.

		if (workspaceUri.scheme === GITHUB_REMOTE_FILE_SCHEME || workspaceUri.scheme === SessionType.CopilotCloud) {
			return [CopilotCloudSessionType];
		}

• Files reviewed: 2/2 changed files
• Comments generated: 2