fix(claude): remove invalid fields from Claude Code settings.json files

## Problem
Claude Code is reporting invalid settings in two configuration files:
- `.claude/settings.json` (project-level)
- `~/.claude/settings.json` (user-level)

Both files contain unrecognized fields that need to be removed or migrated to valid configuration options.

## Invalid Fields Detected
- `defaultMode`
- `autoUpdates`
- `verbose`
- `additionalDirectories`

## Solution
These fields need to be either:
1. Removed if they're no longer supported
2. Migrated to their correct field names if they've been renamed
3. Moved to the appropriate configuration location if they belong elsewhere

## References
- [Claude Code Settings Documentation](https://docs.anthropic.com/en/docs/claude-code/settings)

## Acceptance Criteria
- [ ] Remove invalid fields from `.claude/settings.json`
- [ ] Remove invalid fields from `~/.claude/settings.json`
- [ ] Verify `/doctor` command shows no invalid settings
- [ ] Update any setup scripts that may be creating these invalid fields

Inspect .claude/settings.json and search the repository's setup scripts for the listed fields. Compare each setting with the linked Claude Code documentation, then verify the project configuration and any generated user configuration with /doctor; done means no invalid-settings warnings remain.

Written by the indexing model from the issue text.