deprecate 'entire checkpoint rewind' ahead of removal

The command stays functional but prints a removal notice to stderr and is excluded from help and completion (cobra hides deprecated commands). The hidden top-level 'rewind' shortcut now carries the same removal deprecation instead of a hideAsAlias hint pointing at the equally deprecated canonical form, registered like the existing 'reset' precedent.

Test helpers that parse 'rewind --list' JSON (integration TestEnv and the e2e entire package) now capture stdout separately so the stderr notice doesn't corrupt the JSON.