feat: verb subtype + updateRelation + requireSubtype enforcement

Brings verbs to first-class parity with nouns. The 7.29.0 subtype primitive
shipped for entities only; this release ships the symmetric verb mirror plus
the enforcement layer for ensuring every entity AND every relationship has
both type AND subtype.

Layer V1 — verb subtype mirror
- HNSWVerbWithMetadata.subtype + STANDARD_VERB_FIELDS set + resolveVerbField()
- Relation<T>.subtype, RelateParams<T>.subtype, UpdateRelationParams<T> extended,
  GetRelationsParams.subtype, GraphConstraints.subtype (for find connected)
- relate() persists subtype on verbMetadata + GraphVerb + transaction ops
- getRelations({ type, subtype }) fast-path filter with set membership
- find({ connected: { via, subtype, depth } }) traversal filter (depth-1 on
  the JS path; explicit error on depth > 1 pointing at Cortex native)
- verbsToRelations + storage destructure sites surface subtype to top-level
- All three graph-index fast-path queries (getVerbsBySource/ByTarget) enrich
  with subtype from metadata

Layer V2 — updateRelation() closes a pre-7.30 gap
- New first-class verb update method (parallel to update() for nouns)
- Changes subtype/type/weight/confidence/data/metadata in place
- Re-indexes in graph adjacency when verb type changes; id preserved
- validateUpdateRelationParams enforces id + at-least-one-field-to-update

Layer V3 — verb subtype storage rollup
- verbSubtypeCountsByType: Map<number, Map<string, number>> on BaseStorage
- verbSubtypeByIdCache for self-heal during update/delete
- incrementVerbSubtypeCount + decrementVerbSubtypeCount maintain state
- loadVerbSubtypeStatistics + saveVerbSubtypeStatistics persist to
  _system/verb-subtype-statistics.json (mirrors noun-side shape)
- rebuildVerbSubtypeCounts for poison recovery / explicit repair
- getVerbSubtypeCountsByType accessor for the public counts API
- Wired into init() / flushCounts() / saveVerbMetadata / deleteVerbMetadata

Layer V4 — verb counts API + relationshipSubtypesOf
- brain.counts.byRelationshipSubtype(verb, subtype?) — O(1) breakdown or point
- brain.counts.topRelationshipSubtypes(verb, n) — top N by count
- brain.relationshipSubtypesOf(verb) — sorted distinct subtypes

Layer V5 — migrateField extended to verbs
- New entityKind?: 'noun' | 'verb' | 'both' option (default 'noun')
- Mirror verb iteration via storage.getVerbs() with same path semantics
- verbToRelationLike + buildRelationMigrationUpdate helpers project the
  storage verb shape onto the Entity<T>-shaped surface readPath understands
- Routes through new updateRelation() for the verb-side rewrite

Enforcement (opt-in in 7.30, default in 8.0)
- brain.requireSubtype(type, options) — unified API for NounType OR VerbType.
  Registers per-type rules with optional values whitelist; composes with the
  brain-wide flag.
- new Brainy({ requireSubtype: true }) — brain-wide strict mode. Every public
  write path validates the pairing guarantee.
- { except: [NounType.Thing, ...] } form for catch-all type exemptions
- Atomic-fail semantics on addMany / relateMany — pre-validate every item
  before any storage write, throw on first failure with item index
- Per-type rules + brain-wide flag both throw with descriptive messages
- VFS infrastructure bypass via metadata.isVFSEntity / isVFS markers so
  brain's own VFS writes don't get rejected when strict mode is on

VFS labeling — concrete subtypes for infrastructure entities
- VFS root: NounType.Collection + subtype: 'vfs-root' (was bare Collection)
- VFS directories: subtype: 'vfs-directory'
- VFS files: subtype: 'vfs-file' (NounType still mime-based)
- VFS containment edges: VerbType.Contains + subtype: 'vfs-contains'
- Lets consumers cleanly enumerate VFS state via find({ subtype: 'vfs-file' })
  and distinguish Brainy's VFS Collections from user-created Collections

Docs
- docs/guides/subtypes-and-facets.md extended with Layer V (Verbs) section +
  Enforcement section. New full reference at the bottom split into Layer 1
  (nouns), Layer V (verbs), Layer 2 (facets), Layer 3 (migration), Enforcement.
- docs/api/README.md adds updateRelation(), getRelations({ subtype }), the
  three verb-side counts methods, requireSubtype(), and the brain-wide
  constructor option. relate() params include subtype.
- docs/DATA_MODEL.md adds a Subtype-for-VerbType section + STANDARD_VERB_FIELDS
- docs/architecture/finite-type-system.md extends Principle 1a to verbs
- docs/QUERY_OPERATORS.md adds a verb-subtype filter section covering
  getRelations and find({connected, subtype}) traversal
- README.md "Subtypes" section now shows both noun + verb in one example +
  the enforcement APIs
- RELEASES.md v7.30.0 entry with the full noun/verb capability parity matrix

Tests
- tests/integration/verb-subtype-and-enforcement.test.ts — 30 new tests
  covering V1 round-trips, V1 set membership, updateRelation in place,
  updateRelation preservation, V2 counts breakdown + point + topN + distinct,
  V2 decrements on unrelate, V2 re-routes on updateRelation, V3 depth-1
  traversal filter, V3 depth>1 explicit error, V4 verb migration, V4 both
  entity kinds, V4 readBoth preservation, V5 per-type required rejection,
  V5 vocabulary rejection, V5 on-vocab acceptance, V5 verb-side enforcement,
  V5 addMany atomic-fail, V5 relateMany atomic-fail, V5 update enforcement,
  V5 updateRelation enforcement, V5 brain-wide strict mode, V5 except clause.

Verification
- Unit suite: 1468/1468 passing
- Noun subtype integration (7.29 carryover): 26/26 passing
- Verb subtype + enforcement integration: 30/30 passing
- Type-check: clean
- Build: clean
- Public closed-source reference audit: clean

Internal 8.0 spec
- .strategy/BRAINY-8.0-SUBTYPE-CONTRACT.md (gitignored, not in npm artifact)
  documents the contract upgrade Cortex 3.0 implements against: required-by-
  default subtype, SubtypeRegistry typing hook, native simplification,
  multi-hop traversal native fast path, brain.fillSubtypes() migration helper.
  Coordinated via PLATFORM-HANDOFF rows CTX-SUBTYPE-PARITY-V2 (7.30 parallel
  work) and CTX-SUBTYPE-8.0-CONTRACT (8.0 spec).
This commit is contained in:
David Snelling 2026-06-05 11:15:52 -07:00
parent 8c68396e71
commit c0d326b36d
14 changed files with 2180 additions and 68 deletions

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@ -221,6 +221,47 @@ await brain.add({
`subtype` lives at the **top level** — NOT inside `metadata`, NOT inside `data`. That's how `find({ type, subtype })` routes through the standard-field fast path (column-store hit) instead of the metadata fallback. See **[Subtypes & Facets](./guides/subtypes-and-facets.md)** for the full guide including `trackField()` and `migrateField()`.
### Subtype — sub-classification within a VerbType (7.30+)
Relationships are first-class citizens too. Every verb (`VerbType`) gets the same `subtype` primitive — a `ReportsTo` relationship might carry `subtype: 'direct'` vs `'dotted-line'`; a `RelatedTo` edge might carry `'spouse'` / `'sibling'` / `'colleague'`. Same shape as the noun side: flat string, no hierarchy, top-level standard field on `HNSWVerbWithMetadata` and on the public `Relation<T>`:
```typescript
await brain.relate({
from: ceoId,
to: vpId,
type: VerbType.ReportsTo,
subtype: 'direct', // top-level standard field
metadata: { since: '2025-Q1' } // user-custom fields stay in metadata
})
```
Fast-path filter on the verb side:
```typescript
const direct = await brain.getRelations({
from: ceoId,
type: VerbType.ReportsTo,
subtype: 'direct'
})
```
The verb-side rollup at `_system/verb-subtype-statistics.json` mirrors the noun-side `_system/subtype-statistics.json` — same shape, same self-heal machinery. Per-VerbType-per-subtype counts are O(1) via `brain.counts.byRelationshipSubtype()`.
Verbs and nouns now have full capability parity — every API on the noun side has a verb-side mirror, including the new `brain.updateRelation()` (which closed a pre-7.30 gap where relationships had no update path).
### Standard verb fields
The verb-side equivalent of `STANDARD_ENTITY_FIELDS` is `STANDARD_VERB_FIELDS`, exported from `src/coreTypes.ts`. Verb-specific standard fields:
| Field | Description |
|---|---|
| `verb` | The VerbType enum value |
| `sourceId` / `targetId` | The two endpoints of the relationship |
| `subtype` | Sub-classification within the VerbType (7.30+) |
| `confidence`, `weight`, `createdAt`, `updatedAt`, `service`, `createdBy`, `data` | Same semantics as the noun-side standard fields |
The companion `resolveVerbField(verb, field)` helper resolves field paths the same way `resolveEntityField` does for nouns: standard fields first, metadata fallback for everything else.
---
## See Also

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@ -214,6 +214,37 @@ brain.find({
See the **[Subtypes & Facets guide](./guides/subtypes-and-facets.md)** for the full surface.
### Filter relationships by subtype (7.30+)
Verbs are first-class peers — `getRelations()` and graph traversal both honor subtype filters on the fast path:
```typescript
// Filter relationships by VerbType subtype
const direct = await brain.getRelations({
from: ceoId,
type: VerbType.ReportsTo,
subtype: 'direct'
})
// Set membership on verb subtype
const all = await brain.getRelations({
from: ceoId,
type: VerbType.ReportsTo,
subtype: ['direct', 'dotted-line']
})
// Graph traversal — subtype filters traversal edges (depth-1 in 7.30 JS path;
// multi-hop subtype filtering lands on Cortex native)
const reports = await brain.find({
connected: {
from: ceoId,
via: VerbType.ReportsTo,
subtype: 'direct',
depth: 1
}
})
```
### Combine semantic search with filters
```typescript

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@ -608,9 +608,10 @@ Create a typed relationship between entities.
const relId = await brain.relate({
from: sourceId,
to: targetId,
type: VerbType.RelatedTo,
data: 'Collaborated on the research paper', // Optional: content for this edge
metadata: { // Optional: structured edge fields
type: VerbType.ReportsTo,
subtype: 'direct', // Optional: sub-classification
data: 'Collaborated on the research paper', // Optional: content for this edge
metadata: { // Optional: structured edge fields
strength: 0.9,
role: 'primary author'
}
@ -621,6 +622,7 @@ const relId = await brain.relate({
- `from`: `string` - Source entity ID (must exist)
- `to`: `string` - Target entity ID (must exist)
- `type`: `VerbType` - Relationship type
- `subtype?`: `string` - Per-product sub-classification within the VerbType (top-level standard field, fast-path indexed). See [Subtypes & Facets](../guides/subtypes-and-facets.md).
- `data?`: `any` - Content for the relationship (overrides auto-computed vector)
- `metadata?`: `object` - Structured edge fields
- `weight?`: `number` - Connection strength (0-1, default: 1.0)
@ -631,6 +633,35 @@ const relId = await brain.relate({
---
### `updateRelation(params)``Promise<void>`
Update an existing relationship. Mirror of `update()` for verbs — closed a long-standing gap (verbs had no update path before 7.30).
```typescript
// Change the subtype on an existing relationship
await brain.updateRelation({ id: relId, subtype: 'dotted-line' })
// Update weight + confidence
await brain.updateRelation({ id: relId, weight: 0.7, confidence: 0.9 })
// Change verb type (re-indexes in graph adjacency, id preserved)
await brain.updateRelation({ id: relId, type: VerbType.WorksWith })
```
**Parameters:**
- `id`: `string` - Relationship ID (required)
- `type?`: `VerbType` - Change verb type (re-indexes in graph adjacency)
- `subtype?`: `string` - Change sub-classification (omit to preserve existing)
- `weight?`: `number` - New weight (0-1)
- `confidence?`: `number` - New confidence (0-1)
- `data?`: `any` - New content
- `metadata?`: `object` - Metadata to merge (or replace with `merge: false`)
- `merge?`: `boolean` - Merge or replace metadata (default: true)
**Returns:** `Promise<void>`
---
### `getRelations(params)``Promise<Relation[]>`
Get relationships for an entity.
@ -647,14 +678,32 @@ const related = await brain.getRelations({
from: entityId,
type: VerbType.Contains
})
// Filter by subtype (fast path, column-store hit)
const direct = await brain.getRelations({
from: entityId,
type: VerbType.ReportsTo,
subtype: 'direct'
})
// Set membership on subtype
const all = await brain.getRelations({
from: entityId,
type: VerbType.ReportsTo,
subtype: ['direct', 'dotted-line']
})
```
**Parameters:**
- `from?`: `string` - Source entity ID
- `to?`: `string` - Target entity ID
- `type?`: `VerbType` - Filter by relationship type
- `type?`: `VerbType | VerbType[]` - Filter by relationship type
- `subtype?`: `string | string[]` - Filter by VerbType subtype (top-level standard field, fast path)
- `service?`: `string` - Multi-tenancy filter
- `limit?`: `number` - Pagination limit (default: 100)
- `offset?`: `number` - Pagination offset
**Returns:** `Promise<Relation[]>` - Matching relationships
**Returns:** `Promise<Relation[]>` - Matching relationships (each with `subtype` at top level when set)
---
@ -1970,6 +2019,81 @@ brain.subtypesOf(NounType.Person)
// → ['customer', 'employee', 'vendor']
```
#### `counts.byRelationshipSubtype(verb, subtype?)``Record<string, number> | number`
Verb-side mirror of `counts.bySubtype`. O(1) per-VerbType-per-subtype counts.
```typescript
brain.counts.byRelationshipSubtype(VerbType.ReportsTo)
// → { direct: 12, 'dotted-line': 3 }
brain.counts.byRelationshipSubtype(VerbType.ReportsTo, 'direct')
// → 12
```
#### `counts.topRelationshipSubtypes(verb, n=10)``Array<[subtype, count]>`
Top N subtypes for a `VerbType` ranked by count.
```typescript
brain.counts.topRelationshipSubtypes(VerbType.ReportsTo, 3)
// → [['direct', 12], ['dotted-line', 3]]
```
#### `relationshipSubtypesOf(verb)``string[]`
Sorted distinct subtypes seen for a `VerbType`.
```typescript
brain.relationshipSubtypesOf(VerbType.ReportsTo)
// → ['direct', 'dotted-line']
```
#### `requireSubtype(type, options?)``void`
Register subtype enforcement for a specific `NounType` or `VerbType`. Unified API for nouns and verbs. Composes with the brain-wide `requireSubtype` constructor flag.
```typescript
// Lock down Person sub-classification
brain.requireSubtype(NounType.Person, {
values: ['employee', 'customer', 'vendor'],
required: true
})
// Lock down management edges
brain.requireSubtype(VerbType.ReportsTo, {
values: ['direct', 'dotted-line'],
required: true
})
```
**Parameters:**
- `type`: `NounType | VerbType` - The type to register
- `options.values?`: `string[]` - Vocabulary whitelist (rejects off-vocab values)
- `options.required?`: `boolean` - Whether subtype is required (default: `true`)
#### Brain-wide strict mode — `new Brainy({ requireSubtype })`
Constructor option that enforces subtype on every `add()` / `addMany()` / `update()` / `relate()` / `relateMany()` / `updateRelation()` for every type:
```typescript
// Every write must include subtype
const brain = new Brainy({ requireSubtype: true })
// Exempt specific types (e.g. catch-all Thing)
const brain2 = new Brainy({
requireSubtype: { except: [NounType.Thing, NounType.Custom] }
})
```
When strict mode is on:
- Every public write path checks the pairing guarantee.
- `addMany()` / `relateMany()` validate all items BEFORE any storage write — atomic-fail, no partial writes.
- Brainy's own VFS infrastructure writes bypass via the `metadata.isVFSEntity: true` marker.
- Per-type registrations always apply regardless of the brain-wide flag.
Becomes the default in 8.0.0.
#### `trackField(name, options?)``void`
Register a metadata field for cardinality + per-NounType breakdown stats. With `values: [...]`, validates against the whitelist on `add()`/`update()`.

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@ -467,7 +467,11 @@ brain.counts.bySubtype(NounType.Person)
// → { employee: 12, customer: 847 }
```
Subtype has its own statistics rollup (`_system/subtype-statistics.json`) maintained alongside `nounCountsByType`, so per-subtype counts stay O(1) at billion scale. Full guide: **[Subtypes & Facets](../guides/subtypes-and-facets.md)**.
Subtype has its own statistics rollup (`_system/subtype-statistics.json`) maintained alongside `nounCountsByType`, so per-subtype counts stay O(1) at billion scale.
The same principle applies to **VerbTypes** (7.30+): the 127-verb taxonomy is intentionally coarse, and `subtype` is the per-product axis for relationships too. A `ReportsTo` relationship might carry `subtype: 'direct'` vs `'dotted-line'`; a `RelatedTo` edge might carry `'spouse'` / `'colleague'`. Verb-side rollup lives at `_system/verb-subtype-statistics.json` with identical shape to the noun-side rollup. Per-VerbType-per-subtype counts are O(1) via `brain.counts.byRelationshipSubtype()`. Brainy's design is fully symmetric — nouns and verbs are first-class peers with identical capability surfaces.
Full guide: **[Subtypes & Facets](../guides/subtypes-and-facets.md)**.
### 2. Semantic not Structural

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@ -271,8 +271,199 @@ await brain.counts.byField('status', { type: NounType.Event })
await brain.migrateField({ from: 'metadata.kind', to: 'subtype' })
```
## Layer V — `subtype` on relationships (verbs)
Relationships are first-class citizens too. Every verb (`VerbType`) gets the same `subtype` primitive: a `ReportsTo` relationship might carry `subtype: 'direct'` vs `'dotted-line'`; a `RelatedTo` edge might carry `'spouse'` / `'sibling'` / `'colleague'`. Same shape as the noun side: flat string, no hierarchy, top-level standard field, indexed on the fast path.
### Write
```typescript
const ceoId = await brain.add({ type: NounType.Person, subtype: 'employee', data: 'Avery' })
const vpId = await brain.add({ type: NounType.Person, subtype: 'employee', data: 'Jordan' })
const matrixId = await brain.add({ type: NounType.Person, subtype: 'contractor', data: 'Sam' })
await brain.relate({
from: ceoId,
to: vpId,
type: VerbType.ReportsTo,
subtype: 'direct'
})
await brain.relate({
from: ceoId,
to: matrixId,
type: VerbType.ReportsTo,
subtype: 'dotted-line'
})
```
### Read & filter
```typescript
// Direct reports — fast path filter (column-store hit, not metadata fallback)
const direct = await brain.getRelations({
from: ceoId,
type: VerbType.ReportsTo,
subtype: 'direct'
})
// Set membership
const allReports = await brain.getRelations({
from: ceoId,
type: VerbType.ReportsTo,
subtype: ['direct', 'dotted-line']
})
```
### Update (new — `updateRelation()`)
Verbs previously had no update method — the only way to change a relationship was delete-then-recreate. 7.30 closes that gap:
```typescript
// Promote a dotted-line report to direct without losing the edge id
await brain.updateRelation({ id: relationId, subtype: 'direct' })
// Or change weight/confidence
await brain.updateRelation({ id: relationId, weight: 0.5, confidence: 0.9 })
```
### Traversal filter
`find({ connected, subtype })` filters traversal edges by their subtype. Composes with `via` (verb-type filter):
```typescript
// All direct reports two hops deep (will be supported in Cortex; for now depth-1)
const directChain = await brain.find({
connected: {
from: ceoId,
via: VerbType.ReportsTo,
subtype: 'direct',
depth: 1
}
})
```
Multi-hop subtype filtering (`depth > 1`) lights up on the Cortex native path; the JS path throws today rather than return incorrect partial results.
### Counts
Same shape as the noun-side counts API:
```typescript
brain.counts.byRelationshipSubtype(VerbType.ReportsTo)
// → { direct: 12, 'dotted-line': 3 }
brain.counts.byRelationshipSubtype(VerbType.ReportsTo, 'direct') // O(1) point
// → 12
brain.counts.topRelationshipSubtypes(VerbType.ReportsTo, 3)
// → [['direct', 12], ['dotted-line', 3]]
brain.relationshipSubtypesOf(VerbType.ReportsTo)
// → ['direct', 'dotted-line']
```
These are O(1) lookups backed by the persisted `_system/verb-subtype-statistics.json` rollup — same self-heal machinery as the noun-side rollup.
### Migrate verb fields
`migrateField()` now walks verbs too:
```typescript
// Migrate verb-side metadata.kind → top-level subtype
await brain.migrateField({
from: 'metadata.kind',
to: 'subtype',
entityKind: 'verb'
})
// Or migrate both nouns and verbs in one pass
await brain.migrateField({
from: 'metadata.kind',
to: 'subtype',
entityKind: 'both'
})
```
Default is `entityKind: 'noun'` (backward-compatible with 7.29).
## Enforcement — `requireSubtype()` + brain-wide strict mode
By default (7.30) subtype is optional. Two complementary opt-in mechanisms let you enforce the pairing of type + subtype on every write:
### Per-type registration
Mark a specific `NounType` or `VerbType` as requiring a subtype, optionally with a fixed vocabulary:
```typescript
brain.requireSubtype(NounType.Person, {
values: ['employee', 'customer', 'vendor'],
required: true
})
brain.requireSubtype(VerbType.ReportsTo, {
values: ['direct', 'dotted-line'],
required: true
})
// Now this throws — Person requires a subtype:
await brain.add({ type: NounType.Person, data: 'no subtype' })
// And this throws — 'matrix' isn't in the registered vocabulary:
await brain.relate({
from: a,
to: b,
type: VerbType.ReportsTo,
subtype: 'matrix'
})
```
### Brain-wide strict mode
Enforce on every write across the whole brain:
```typescript
const brain = new Brainy({ requireSubtype: true })
// Allow specific types to omit subtype (e.g. catch-all `Thing`)
const brain2 = new Brainy({
requireSubtype: { except: [NounType.Thing, NounType.Custom] }
})
```
When strict mode is on:
- Every `add()` / `addMany()` / `update()` / `relate()` / `relateMany()` / `updateRelation()` rejects writes missing a subtype on a non-exempt type.
- `addMany()` and `relateMany()` validate every item BEFORE any storage write — atomic-fail semantics, no partial writes.
- Per-type rules registered via `requireSubtype()` compose with the brain-wide flag; specific rules win when both apply.
- Brainy's own internal writes (VFS root, VFS directories, VFS file entities) bypass enforcement via the `metadata.isVFSEntity: true` infrastructure marker.
### Migrating to strict mode on an existing brain
`brain.migrateField()` is your friend — populate `subtype` from an existing convention before flipping strict mode on:
```typescript
// Step 1: backfill subtype from your existing metadata.kind convention
await brain.migrateField({
from: 'metadata.kind',
to: 'subtype',
entityKind: 'both'
})
// Step 2: register the vocabulary
brain.requireSubtype(NounType.Person, {
values: ['employee', 'customer', 'vendor'],
required: true
})
// Step 3: future writes must have a subtype matching the vocabulary
await brain.add({ type: NounType.Person, subtype: 'employee', data: '...' })
```
## Reference
### Layer 1 — `subtype` (nouns)
- `brain.add({ ..., subtype: 'value' })` — write the field
- `brain.update({ id, subtype: 'value' })` — change the field
- `brain.find({ type, subtype })` — filter (fast path)
@ -280,6 +471,29 @@ await brain.migrateField({ from: 'metadata.kind', to: 'subtype' })
- `brain.counts.bySubtype(type, subtype?)` — O(1) counts
- `brain.counts.topSubtypes(type, n?)` — top N by count
- `brain.subtypesOf(type)` — distinct subtype list
### Layer V — `subtype` (verbs / relationships)
- `brain.relate({ ..., subtype: 'value' })` — write the field
- `brain.updateRelation({ id, subtype, type?, weight?, ... })` — change a relationship
- `brain.getRelations({ subtype })` — filter (fast path)
- `brain.getRelations({ subtype: ['a', 'b'] })` — set membership
- `brain.find({ connected: { via, subtype, depth } })` — traversal filter
- `brain.counts.byRelationshipSubtype(verb, subtype?)` — O(1) counts
- `brain.counts.topRelationshipSubtypes(verb, n?)` — top N by count
- `brain.relationshipSubtypesOf(verb)` — distinct subtype list
### Layer 2 — generic facets
- `brain.trackField(name, { perType?, values? })` — register a facet
- `brain.counts.byField(name, { type? })` — facet counts
- `brain.migrateField({ from, to, readBoth?, batchSize?, onProgress? })` — rewrite a field
### Layer 3 — migration
- `brain.migrateField({ from, to, readBoth?, batchSize?, onProgress?, entityKind? })` — rewrite a field (nouns, verbs, or both)
### Enforcement
- `brain.requireSubtype(type, { values?, required })` — per-`NounType` / `VerbType` rule
- `new Brainy({ requireSubtype: true })` — brain-wide strict mode
- `new Brainy({ requireSubtype: { except: [type, ...] } })` — strict with exemptions