feat(namespace): NO SPECIAL NAMES + storage fidelity — the ruled completion of the field-addressing law

The write side of the law, ruled 2026-08-03: data is either in main space
where developers can use anything, or it is in system.*.

- The reserved-name write door DIES: add/update/relate/updateRelation
  metadata bags accept EVERY name (confidence, type, id, data, level,
  content, ...) as ordinary user fields — indexed, filterable, sortable,
  aggregatable, identical to any other field. The remap/enforce/warn
  machinery, the reservedFieldPolicy config (now a typed init refusal),
  and the compile-time metadata key bans are all removed. The one write
  refusal left: keys spelled 'system.*' (namespace forgery), now enforced
  on all four write doors.
- STORED RECORDS GO NESTED (v2): engine fields top-level, the user bag
  nested verbatim under 'metadata', sealed by a format stamp — by-name
  storage discrimination is unsound once colliders are admitted. Legacy
  flat records stay readable forever through the shape-aware splitters
  (sound for them: the old door refused colliders). Time travel rides the
  same split (generation store snapshots whole records).
- Name-based index exclusions DIE: user frame indexes every name; the
  excludeFields/indexedFields knobs and their silent-[] holes are gone;
  bulk-payload protection is value-shape only, uniform across names.
- Consumer-sweep findings fixed in the same wave: per-type counts read
  the frozen 'system.type' column (addToIndex sort, affinity tracking,
  cold-count rehydration, VFS type bitmaps — legacy 'noun' fallback for
  pre-rebuild reads); resolveHiddenIds addresses 'system.visibility'
  (bare 'visibility' was a silent no-op under the law — VFS/system
  entities leaked into default reads).
- Fidelity fallout fixed in the owning layers: readEntityFieldAddress
  reads the bag first (colliders were absent-shadowed by its own guard)
  and never serves system addresses from the bag; blob history refs read
  the bag shape-aware; migration transforms now receive ONE normalized
  view (engine fields + nested bag) regardless of stored era, and stray
  flat-habit keys refuse with the fix in the message.
- THE REOPEN-COLLIDER CONFORMANCE CASE (required before any RC counts as
  gates-green): all ten collider names + plumbing names written as user
  fields, verified verbatim + queryable across live reads, flush+reopen,
  a forced epoch rebuild, and asOf time travel; relation mirror; forgery
  refusals; legacy flat-record compat. 8/8 green.

Gates: unit 1901/1901 (exit 0) · integration 758 (exit 0) · conformance
27/27 (exit 0) · consumer test sweep migrated (10 files).

tests/regression/metadata-index-cleanup.unit.test.ts

@@ -244,7 +244,10 @@ describe('Metadata index cleanup after remove / removeMany', () => {
       const noConfidenceId = await addEntity({ type: 'thing' })
       const withConfidenceId = await addEntity({ type: 'thing', confidence: 0.9 })
 
-      const results = await brain.find({ where: { confidence: { exists: true } } })
+      // system.confidence — confidence is an engine scalar (an add() param),
+      // never a metadata field; bare 'confidence' now addresses the user's
+      // own metadata bag under the sealed field-addressing law.
+      const results = await brain.find({ where: { 'system.confidence': { exists: true } } })
       const ids = results.map(r => r.id)
 
       expect(ids).toContain(withConfidenceId)
@@ -255,7 +258,8 @@ describe('Metadata index cleanup after remove / removeMany', () => {
       const noWeightId = await addEntity({ type: 'thing' })
       const withWeightId = await addEntity({ type: 'thing', weight: 0.5 })
 
-      const results = await brain.find({ where: { weight: { exists: true } } })
+      // system.weight — same reasoning as system.confidence above.
+      const results = await brain.find({ where: { 'system.weight': { exists: true } } })
       const ids = results.map(r => r.id)
 
       expect(ids).toContain(withWeightId)
@@ -269,11 +273,12 @@ describe('Metadata index cleanup after remove / removeMany', () => {
       const id = await addEntity({ type: 'thing' })
       await brain.remove(id)
 
-      // Entity must not appear in any confidence query
-      const existsTrue = await brain.find({ where: { confidence: { exists: true } } })
+      // Entity must not appear in any confidence query. system.confidence —
+      // same addressing as the two tests above.
+      const existsTrue = await brain.find({ where: { 'system.confidence': { exists: true } } })
       expect(existsTrue.map(r => r.id)).not.toContain(id)
 
-      const existsFalse = await brain.find({ where: { confidence: { exists: false } } })
+      const existsFalse = await brain.find({ where: { 'system.confidence': { exists: false } } })
       expect(existsFalse.map(r => r.id)).not.toContain(id)
     })
   })