Support claude config in all workspace folders and workspace file directory (multi-root workspaces)

Feature Request

In multi-root VS Code workspaces, Claude Code only scans the first/primary
workspace folder for claude config such as claude.md, .mcp.json, commands. This makes it unnecessarily hard to configure
Claude in multi-root setups.

Proposed behavior

Claude Code should scan for Claude config in:

1. All workspace folders listed in the .code-workspace file (not just the first)
2. The directory containing the .code-workspace file itself
3. User-level ~/.claude/.mcp.json (currently also not supported in the VS Code extension)

Current behavior

Only the first workspace folder root is scanned. This forces users to place Claude config
in a specific folder that may not be the most logical location
for their project structure.

Environment

• Claude Code VS Code extension
• Multi-root workspace