Allow configurable memory directory (e.g., inside git repo)

Currently, Claude Code's auto-memory is stored at ~/.claude/projects/<project-path>/memory/ which is:

• Machine-specific (not shared across devices)
• Outside the repo (not version-controlled)
• Invisible to team members

Request: Allow configuring the memory directory path, e.g., in .claude/settings.json or CLAUDE.md:

{
  "memory_directory": ".claude-memory"
}

This way memory files can live inside the git repo and be:

• Shared across the user's devices
• Version-controlled (see history of what Claude learned)
• Optionally shared with team members
• Backed up with the rest of the project

Current workaround: Symlink ~/.claude/projects/.../memory/ → repo directory. Works but fragile and per-machine.