decompose wave 5 — contract suite: audit-first split of the verification backlog (engines' columns already discharge most rows; map in review-wave-5's appendix), seven mechanism-grouped suite-row tasks (queue depth, scheduler, tx commit-atomicity, streams, locks, wakes, opts/backoff equivalence), two engine-side hardening tasks (sqlite commit-error arm, pg F-1 defense-in-depth), and the review-wave-5 gate that flips the engine specs to stable

tasks/sqlite-commit-error-arm.md

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+---
+id: sqlite-commit-error-arm
+name: SQLite engine — commit-error-arm coverage (wave-3 review's deferred test)
+status: pending
+depends_on: []
+scope: narrow
+risk: medium
+impact: isolated
+level: implementation
+tags: [wave-5, sqlite-engine, tests]
+---
+
+## Description
+
+Land the wave-3 review gate's deferred coverage item
+(`tasks/review-wave-3.md` Notes: "Coverage of the commit-error arm —
+no test induces a failing `COMMIT` ... natural home is wave 5's suite
+hardening"): a test that drives a failing `COMMIT` through the SQLite
+engine's `commit` path and pins the fix the review verified by
+code-read — the writer slot is replenished via the `reopen` closure on
+the failed `COMMIT` (no stranding), the error surfaces as the opaque
+`Database`, and the store remains fully usable afterward (subsequent
+`begin_tx`/auto-commit ops work).
+
+The injection mechanism is this task's to find — candidates: a
+`PRAGMA max_page_count` squeeze forcing `SQLITE_FULL` on a
+space-consuming commit, or a `cfg(test)` fault seam in the seam layer
+if the PRAGMA route cannot hit the COMMIT arm deterministically. The
+wave-4 fix batch's `cfg(test)` config-seam precedent
+(`pg-fix-forwarder-reconnect`) is the house pattern if a seam is
+needed. Prefer the least-invasive mechanism that deterministically
+reaches the arm; document the choice.
+
+If the same session has cheap room for it, the waves-1–2 review's
+optional add — the watcher reconnect-*success* path test (upstream's
+W-1 test drives only the failure path; "a reconnect success test would
+require a file appearing mid-run") — rides here **only if** the
+engine kept the current watcher shape and the test is genuinely cheap;
+otherwise leave it recorded as not-taken in Notes (it was a
+suggestion, not an order).
+
+## Acceptance Criteria
+
+- [ ] A test induces a failing `COMMIT` on the SQLite engine and pins:
+      error surfaces (`Database`), writer slot replenished (a
+      subsequent `begin_tx` succeeds), no partial-commit residue
+- [ ] The injection mechanism documented in Notes (PRAGMA vs seam, and
+      why)
+- [ ] The watcher reconnect-success test either landed or explicitly
+      recorded as not-taken with the reason
+- [ ] `cargo test -p alkstore-sqlite` green server-less; clippy
+      `-D warnings`; fmt clean
+
+## References
+
+- tasks/review-wave-3.md (Notes: the deferred commit-error-arm coverage)
+- tasks/sqlite-engine-seam-tx.md (the `commit` replenish fix the test pins)
+- tasks/pg-fix-forwarder-reconnect.md (the `cfg(test)` seam precedent)
+- docs/reviews/001-waves-1-2-general-review.md §2 (the watcher
+  reconnect-success suggestion)
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion