Land the validated F-265 fix (priorStaged fallback in resources/Table.ts + RecordEncoder.ts, currently uncommitted in the qa-f265 worktree) and include qa888-blob-chain-lmdb as its regression test — r

From QA/dispatch finding (task `qa-wave-2026080114`):

- F-265 — LMDB same-transaction create→(N overwrites)→delete leaks every superseded blob AND orphans the base-store row (baseline `pass 0/fail 4`: 5 leaked blobs + 5/5 orphaned rows per cell, 62.9 MB). The trial fix already in `.claude/worktrees/qa-f265` takes all 4 cells to 0/0, and QA-888 has now discharged the *last* unmeasured caveat (mid-transaction blob replacement) that was holding it back — the fix is validated and ready to land, with P-631 as its ready-made regression anchor.

Inspect the validated changes in resources/Table.ts and RecordEncoder.ts from the qa-f265 worktree, then review the qa888-blob-chain-lmdb regression test and its existing anchor. Done means the fix is committed and the regression test passes for the same-transaction create, overwrite, and delete case without leaked blobs or orphaned rows.

Written by the indexing model from the issue text.