[FEATURE] Allow setting working directory in web session environment configuration

Problem

Claude Code web sessions (claude.ai/code) always start at the repository root. There is no way to configure a different working directory in the environment settings.

For monorepos where project-specific .claude/ configuration (hooks, skills, MCP servers, settings) lives in a subdirectory, this means:

• .claude/settings.json in the subdirectory is never discovered
• SessionStart hooks never fire
• Skills, MCP servers, and other .claude/ config are not loaded

What I tried

| Approach | Result |
|----------|--------|
| cd <subdir> in the setup script | Does not persist — Claude resets working directory to repo root |

Use case

Our monorepo has this structure:

my-platform/                ← repo root (where web session starts)
  apps/
    my-app/                 ← where we work, where .claude/ lives
      .claude/
        settings.json       ← hooks, permissions, plugins
        hooks/              ← SessionStart, PostToolUse, Stop hooks
        skills/
        commands/
      frontend/
      backend/

We built a SessionStart hook that bootstraps the full dev environment in web sessions. It works locally but is invisible to web sessions because they start at the repo root.

Proposed solution

Add a "Working directory" field (path relative to repo root) in the claude.ai/code environment configuration. When set, the session starts in that directory, discovering .claude/ config there.

Example: setting apps/my-app would make the session behave as if claude was launched from apps/my-app/.

Alternative: parent directory traversal

#12962 proposes that Claude Code traverse parent directories to find .claude/settings.json. If that were implemented with downward discovery as well (or if the web session supported walking into known subdirectories), it could also solve this problem — the repo-root session would discover and merge .claude/ config from apps/my-app/. This would be even better since it would fix both web sessions and any context where Claude starts from a parent directory.

Related issues

• #12962 — Settings.json parent directory traversal for monorepos
• #37344 — Hierarchical .claude config discovery in monorepos
• #33131 — Allow customizing the .claude/ directory location
• #2365 — Better monorepo support
• #23627 — Multi-repository support for remote/web sessions
• #36175 — Desktop app: no option to select project directory