autoMemoryDirectory should support relative paths like plansDirectory

Summary

autoMemoryDirectory only accepts ~/-expanded (absolute) paths, while plansDirectory supports paths relative to the project root. This inconsistency makes it impossible to configure "store memory inside the project" globally from user settings.

Current behavior

• plansDirectory docs: "Path is relative to project root. Default: ~/.claude/plans"
• autoMemoryDirectory docs: "Accepts ~/-expanded paths."

Setting "autoMemoryDirectory": ".claude/memory" in either user or local settings is silently ignored — memory continues writing to the default ~/.claude/projects/<project>/memory/ location.

Only absolute paths work, e.g. "/home/user/projects/my-repo/.claude/memory", which means the setting must be duplicated in every repo's .claude/settings.local.json with a hardcoded absolute path.

Expected behavior

autoMemoryDirectory should resolve relative paths against the project root, the same way plansDirectory does. This would allow a single entry in user settings:

{
  "autoMemoryDirectory": ".claude/memory"
}

This would resolve to <project-root>/.claude/memory for every project, enabling version-controlled memory without per-repo configuration.

Workaround

Set an absolute path in each repo's .claude/settings.local.json individually:

{
  "autoMemoryDirectory": "/home/user/projects/my-repo/.claude/memory"
}

This works but doesn't scale and defeats the purpose of user-scope settings.