Allow resuming conversations from different directories

Problem

Conversations are tied to the directory where they were started. If the original directory no longer exists (e.g., deleted git worktree, moved/renamed directory), there's no way to resume that conversation.

The current behavior shows:

This conversation is from a different directory.

To resume, run:
  cd /original/path && claude --resume <session-id>

But if /original/path no longer exists, this is impossible without manually recreating the directory structure.

Use Cases

1. Git worktrees: Developers often create temporary worktrees for PRs/features, then delete them after merging. Conversations from those worktrees become inaccessible.

1. Directory reorganization: Moving or renaming project directories orphans all associated conversations.

1. Disk cleanup: Removing old project directories loses conversation history even if you want to reference it later.

Proposed Solution

Add a --force flag (or similar) to allow resuming a conversation regardless of directory mismatch:

claude --resume <session-id> --force

Or allow specifying a session ID without directory validation:

claude --resume <session-id> --ignore-directory

Current Workarounds

• Manually recreate the original directory path (empty directory works)
• Symlink current location to the old path

Both are cumbersome and shouldn't be necessary.