Why: recovery r3 U8 is approved for implementation through a mergeable PR, and the lock, inode and durability rules need a single spec before code.
Evidence: precheck receipt /tmp/u8-sqlite-instance-guard-precheck-2.json (SELF, exit 0, R0 6a494d3977).
Impact: task card and docs only; no runtime change yet.
Refs: docs/recovery/u8-sqlite-instance-guard.md
Co-authored-by: Cursor <cursoragent@cursor.com>