v2.1.251

## What's changed - Added `PreModelSwitch` and `PostModelSwitch` hook events (block, confirm, or annotate a model switch); `SessionStart` resume hooks now receive session staleness and the estimated re-cache cost - Added live streaming of a foreground subagent's tool calls and results to Remote Control clients (background subagents, the default, still show status only) - Added a Spend limit bar to `/usage` and a `rate_limits.spend_limit` status line field for developers behind a Claude apps gateway with spend limits - Added a per-session prompt-cache line to `/cost` (hit ratio, misses, tokens re-cached, warm/cold) and a matching `prompt_cache` object for status line scripts - Added `attach`, `logs`, `stop`, `respawn`, and `rm` to `claude --help`; the `--resume` message for a running background session now names the exact `claude attach ` command - Fixed file tools (Read, Write, Edit) following a symlink swapped inside the working directory after the permission check, which could read or write outside the approved location - Fixed plugin commands declared in a marketplace entry being able to point outside the plugin directory; such paths are now rejected with a path-traversal error