feat(namespace): aggregation reads under the law + epoch 3 (the key-split rebuild) + THE ARMING COMMIT — the capability constant, the law module, and the typed refusals export from the package root; both engines' conformance suites light on this signal

src/storage/brainFormat.ts

@@ -69,12 +69,15 @@ export const BRAIN_FORMAT_PATH = '_system/brain-format.json'
  * (the 8.0 GA baseline). An on-disk `indexEpoch` that differs from this — or an
  * absent marker — triggers a full derived-index rebuild on open.
  */
-// Epoch 2 (2026-08-03, paired with the native accelerator's same-day release):
-// user metadata fields named `level` become indexable on both engines — the
-// derived posting set changed, so every pre-fix brain must rebuild its
-// metadata index from canonical at first open (poisoned multi-valued `level`
-// columns heal through this rebuild; no bespoke heal path).
-export const EXPECTED_INDEX_EPOCH = 2
+// Epoch 3 (2026-08-03, the namespace-law pair): the index key format split
+// the two namespaces — user fields keep bare flattened keys, the ten system
+// scalars moved to literal 'system.<field>' keys (the legacy 'noun' column
+// spelling died with them). Every brain rebuilds its derived indexes from
+// canonical at first open onto the frozen keys.
+// Epoch 2 (2026-08-03, same day, the interim pair): user metadata fields
+// named `level` became indexable on both engines; poisoned multi-valued
+// `level` columns healed through the rebuild.
+export const EXPECTED_INDEX_EPOCH = 3
 
 /**
  * @description The data-layer format string this build writes and runs as.