v0.7.7

Closes the five remaining audit gaps from the 0.7.6 sweep.

Fixes

• fix(state/reset) — state reset --export <X> validates the export
  against the loaded config before touching state. A typo (--export pa_audi for declared pa_audit) now bails with a hint listing the
  declared names and a follow-up rivet state show command instead of
  silently DELETE-ing zero rows and printing "State reset for export ..."
  as if it worked.

Test infrastructure

• test(path_matrix) — pin data-accounting fields (total_rows,
  files_produced, status, format, compression, export_name)
  from every summary.json produced by rivet run. Catches the class
  of regression where layout matches but row count is wrong.
• test(query_matrix) — NEW. Fourth matrix. Pins PG EXPLAIN (COSTS OFF) plan shape per representative query. Catches operator
  query wrapped in subquery / CTE, planner dropping the PK index, sort
  steps appearing without intent.
• test(gremlin) — added 5 new scenarios (G6–G10): row_count_max
  upper bound, row_count_min boundary inclusivity, NULL handling in
  unique_columns, chunked + sparse-ID quality, multi-export
  one-fails-others-continue.
• test(soak_matrix) — NEW. Fifth matrix. Pins order-of-magnitude
  perf and memory thresholds on a 10k-row PG table per export mode
  (full / chunked / incremental). Catches "50x slower" / "10x memory"
  regressions; tunable thresholds, deliberately generous to avoid
  CI runner noise.
• test(dev/matrices) — orchestrator + taxonomy (Surface /
  Execution / Resources / Compatibility layers) + shared _common/lib/
  for helpers used by ≥2 matrices. run.sh --tier=pr|nightly|release
  binds each matrix to a CI tier.