●RELEASE — Claude Code v2.1.251 landed on August 28 with close to a hundred changes, built around two themes: tightening permissions and sandboxing, and making usage and cost visible●SECURITY — Read, Write, and Edit could follow a symlink swapped inside the working directory after the permission check had passed, reading or writing outside the approved location●SECURITY — Grep and Glob were not applying Read(...) deny rules to files reached through a symlinked search path. Plugin command path traversal was closed off in the same release●COST — /cost now shows a per-session prompt cache line covering hit ratio, misses, tokens re-cached, and warm versus cold, with a matching prompt_cache object for status line scripts●HOOKS — New PreModelSwitch and PostModelSwitch events let you block, confirm, or annotate a model switch, and SessionStart resume hooks now receive staleness and estimated re-cache cost●MODEL — Seat-billed Enterprise now defaults to Opus 5, and /effort saves a default per model. The 50% weekly limit increase runs through August 31, which leaves one day●RELEASE — Claude Code v2.1.251 landed on August 28 with close to a hundred changes, built around two themes: tightening permissions and sandboxing, and making usage and cost visible●SECURITY — Read, Write, and Edit could follow a symlink swapped inside the working directory after the permission check had passed, reading or writing outside the approved location●SECURITY — Grep and Glob were not applying Read(...) deny rules to files reached through a symlinked search path. Plugin command path traversal was closed off in the same release●COST — /cost now shows a per-session prompt cache line covering hit ratio, misses, tokens re-cached, and warm versus cold, with a matching prompt_cache object for status line scripts●HOOKS — New PreModelSwitch and PostModelSwitch events let you block, confirm, or annotate a model switch, and SessionStart resume hooks now receive staleness and estimated re-cache cost●MODEL — Seat-billed Enterprise now defaults to Opus 5, and /effort saves a default per model. The 50% weekly limit increase runs through August 31, which leaves one day