30793c1655
- Replaced per-line hash anchors with file-level hash validation in hashline format, changing anchor syntax from LINE+HASH to bare LINE numbers. - Simplified hashline line separator from pipe (|) to colon (:) and replaced replace operator (->) with colon, added delete operator (!) for explicit line deletion. - Implemented file-read snapshot caching with multi-snapshot ring buffer per path and file-hash-based recovery to detect and recover from stale edits. - Refactored hashline grammar, parser, and execution to support file-level hash binding, anchor-scoped validation, and structural bracket warnings for delete operations. - Updated documentation and test fixtures to reflect new hashline syntax with file hashes, colon separators, and delete operator throughout.