Desktop app: Customize project selection doesn't persist, new sessions don't auto-select default folder

Description

In the Claude Desktop app (Code mode), the "Select folder" button on new sessions no longer auto-selects the configured default project folder. This used to work — the vault folder was always pre-selected when starting a new session.

Current behavior

1. New session: "Select folder" button is blank — no folder pre-selected
2. Customize page: When I select my project folder, it appears momentarily (shows the GitHub remote name Ro-Ma/roni-vault-git as label, correct path /Users/ronim/Documents/roni-vault in tooltip). But navigating away and returning to Customize shows the selection is gone — it doesn't persist.
3. The config file at ~/Library/Application Support/Claude/claude_desktop_config.json has the correct path set under preferences.chillingSlothLocation.customPath, but the app ignores it.

Expected behavior

• New Code sessions should auto-select the configured default project folder
• The Customize page project selection should persist across navigation

Environment

• macOS (Darwin 25.3.0)
• Claude Desktop app, Code mode
• Max plan

Steps to reproduce

1. Open Claude Desktop app
2. Switch to Code mode
3. Click "+ New session"
4. Observe "Select folder" is blank (no default)
5. Go to Customize → select a project folder
6. Navigate back, then return to Customize — selection is gone

Additional context

The underlying config file is correctly set:

{
  "preferences": {
    "chillingSlothLocation": {
      "customPath": "/Users/ronim/Documents/roni-vault"
    }
  }
}

This value is not being read by the app UI. Re-writing the config file and restarting the app does not fix the issue.