[grove]

Scope

Fixes #1198. The parser retains structured JOIN ... USING equality predicates and accepts a repeated nested INNER key only when the predicate proves equality between the exact input columns. Unproven nested keys and NULL-extending outer-join cases remain unsupported.

The change includes parser and differential-refresh coverage for proven and ambiguous chains, mismatched keys, changing rows, and exact result multisets. It preserves the five-alias Delta V1 reference-consumer regression.

Validation

• just fmt and PATH=/opt/homebrew/bin:$PATH just lint pass.
• Unit tests pass locally (2674/2674); the frozen S1 harness check passes.
• Packaged PostgreSQL 18 Testcontainers checks pass for test_v104_delta_reference_consumer_reads_and_acknowledges and test_multi_cycle_full_join_differential.
• CI run 40863373307 is on exact head c58bb41817feeebd0b3fc19c0a2d530c80d696c2, after merging current main 75f2d1f590ea2aa029b18b8ee91332f719b14057. Lint, proof/release evidence, fuzz smoke, static/security checks, upgrade completeness, and S1 checks passed.
• Joint audit run 40863373169 failed in the pinned React compatibility fixture before idle-delivery assertions: the candidate installs pg_trickle 0.108.4, while the pinned React fixture admits only 0.108.0 and 0.108.3. The audit artifact is available here. This is a compatibility admission failure, not a nested USING test failure. React admission and the MDM qualified checksum were not changed.
• Remaining exact-head CI checks are still running.

Review status

This PR is not ready to merge. The compatibility admission block needs an explicitly authorized resolution, all required correctness gates must pass on the exact candidate, and the required sole-owner source review remains outstanding. Do not bypass the pinned admission or change the MDM checksum. Keep #1198 open.

The separate #1168 throughput candidate and unrelated SF-1 TPC-H timeout are not addressed here.

[grove]

CI scope escalation — not merge authorization

The draft job matrix suppresses packaged light E2E tests. I am moving this unqualified candidate into GitHub's “ready for review” state solely to execute the repository's existing, unchanged packaged Delta V1 reference-consumer and light-E2E correctness gates. The requested review state is not an owner approval to merge, change a shipped MDM checksum, publish a release, or activate React escalation. If the full tests find a failure, retain the logs and return this PR to draft while investigating. Keep upstream regression #1198 open until exact passing evidence.

[grove]

CI repair follow-up on head 99e6dbd: the scheduler test now waits for both new refresh history and the expected committed row, since history can advance for a snapshot taken before the insert. The repaired focused Testcontainers test passed four consecutive local runs. just fmt and PATH=/opt/homebrew/bin:$PATH just lint passed. Fresh GitHub CI is running for this head.