Fix "Open in VS Code" not opening workspace for Claude agent sessions

[Copilot]

Clicking "Open in VS Code" from a Claude session opened the session but silently skipped opening the workspace folder. Copilot CLI sessions worked correctly because the folder URI extraction was explicitly gated on CopilotCLISessionType.id.

Changes

• browser/openInVSCode.contribution.ts / electron-browser/openInVSCode.contribution.ts: Replace the session-type guard with the existing isWorkspaceAgentSessionType() helper, which already covers both 'copilotcli' and 'claude-code'.

// Before — Claude sessions always resolved to undefined
const rawFolderUri = activeSession.sessionType === CopilotCLISessionType.id
    ? repo?.workingDirectory ?? repo?.uri
    : undefined;

// After — both Copilot CLI and Claude Code sessions resolve their folder
const rawFolderUri = isWorkspaceAgentSessionType(activeSession.sessionType)
    ? repo?.workingDirectory ?? repo?.uri
    : undefined;

For Claude sessions, repo.uri is already URI.file(workingDirectoryPath), so workingDirectory ?? uri correctly resolves to the working directory for both session types.

[Copilot]

Pull request overview

Fixes the Agents window “Open in VS Code” action so that Claude Code sessions (in addition to Copilot CLI sessions) correctly open the associated workspace folder when launching VS Code.

Changes:

• Switch folder-URI extraction guard from CopilotCLISessionType.id to isWorkspaceAgentSessionType(...) in both web and desktop implementations.
• Add a focused unit test suite covering isWorkspaceAgentSessionType for Copilot CLI, Claude Code, cloud, unknown, and undefined inputs.

Show a summary per file

File	Description
src/vs/sessions/contrib/chat/browser/openInVSCode.contribution.ts	Uses isWorkspaceAgentSessionType to include Claude Code sessions when resolving the folder URI for “Open in VS Code”.
src/vs/sessions/contrib/chat/electron-browser/openInVSCode.contribution.ts	Same session-type gating change for the desktop “Open in VS Code” action path (sibling app / protocol handler).
src/vs/sessions/services/sessions/test/common/session.test.ts	Adds unit tests validating isWorkspaceAgentSessionType behavior across relevant session types.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 0