Adds `openclaw sessions tail` as an operator-facing progress view over session trajectory events, with conservative redaction for prompt text, tool arguments, and tool result bodies. The command supports explicit session keys, store/agent scope, follow mode, relocated trajectory pointer files, and cursor-safe follow across bounded trajectory window rewrites.
Documents the new sessions tail CLI surface in `docs/cli/sessions.md`.
Fixes#83441.
Co-authored-by: zhengzuo0-ai <zheng.zuo0@gmail.com>