fix: scope session list and children to current worktree

[naaa760]

fix: #13782

what does this PR do?

• Issue: Sessions from one worktree appeared in another because list only filtered by project_id.
• Change: Restrict list and children to the current worktree by filtering on directory (worktree root or under it).
• Escape LIKE so %/_ in paths don’t match wrong sessions.

Why:

• Instance.worktree is the request’s work tree root; sessions already store directory under it, so this keeps worktrees separate.

[github-actions]

The following comment was made by an LLM, it may be inaccurate: