[FEATURE] Add Personal User Configuration for AI Assistant Behavior (Separate from Project Settings)

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When working in team environments, all AI behavior customization in Claude Code is shared through the project's CLAUDE.md file. This creates conflicts when team members have different communication preferences. For example, I prefer casual Spanish communication with "tú" and a friendly tone, while my English-speaking teammate prefers formal responses. Currently, we must compromise on a single style or constantly modify the shared configuration, which is disruptive to team workflows and version control.

Proposed Solution

A personal configuration file (e.g., ~/.claude-code/personal-config.md) that works alongside the project's CLAUDE.md. Personal settings would override or complement project settings without affecting teammates.

Users could configure communication tone, language style, personality preferences, and response verbosity.

The system would follow precedence: Personal config > Project CLAUDE.md > Default behavior.

Alternative Solutions

I've tried:

1) Creating personal branches with modified CLAUDE.md (too cumbersome)

2) Starting each session with tone instructions (gets forgotten between sessions)

3) Temporarily editing CLAUDE.md and reverting before commits (error-prone and disruptive). None provide a clean, persistent solution.

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

1. I clone a new project repository with an English CLAUDE.md specifying formal tone
2. I create ~/.claude-code/personal-config.md with Spanish casual preferences
3. When I interact with Claude Code, it responds in casual Spanish with "tú"
4. My teammate uses the same repository but gets formal English responses
5. Both of us have optimal experience without conflicts or shared configuration changes

Additional Context

• Similar feature: Cursor IDE allows personal assistant configuration separate from project settings
• Team benefit: Reduces configuration conflicts and improves individual developer experience
• Technical consideration: Should merge cleanly with existing CLAUDE.md system without breaking current functionality