no-mistakes(document): docs: complete origin subtypes plus #210 host rule

Author: dmealing

CLAUDE.md

@@ -440,7 +440,7 @@ Preserve the following contracts exactly across all language ports:
 - Filter operators: `eq`, `ne`, `gt`, `gte`, `lt`, `lte`, `in`, `like`, `isNull`
 - Object subtypes: `entity` (owns data: own identity, writable sources, lifecycle), `value` (pure shape: NO identity, NO source, ever; constructed — by caller/embedding — never populated; may `extends` entity fields for shape; a value-hosted field may carry `origin.passthrough` but never an assembly origin), `projection` (derived read-only representation: fields `extends`-bound / origin-derived / self-declared-under-external-assembly, all read-only at subtype level; identity optional and MUST extend an entity identity; sources restricted to read-only `@kind`s; the declared field set IS the exposure — inclusive list, fail-closed). A field carrying `origin.*` is derived ⇒ read-only wherever it lives (incl. on entities). An entity's primary source must be a writable `@kind` (read-only kinds only in read role). See [ADR-0028](spec/decisions/ADR-0028-object-taxonomy-projection-value-purity.md). (FR-024 Phase E — `object.projection`/`value` are registered in `expected-registry.json` and the projection/value validation passes [identity pass-through, value-purity, projection-licensing, `@via` inference/cardinality, extends/origin agreement, derived-field providability] are enforced cross-port in all 5 ports. The **B4b** entity-primary-source-readonly cutover [the "writable `@kind`" clause above — `ERR_ENTITY_PRIMARY_SOURCE_READONLY`] + the projection codegen fan-out (read-only DTOs for view-kind projections; FR-015 proc-callables for proc-kind projections; api-docs label `object.projection` units as `projection` and document their generated `<Name>Dto`) are now shipped cross-port; the remaining FR-024 work is the declared-API surface — tracked in #10.)
 - Source subtypes: `rdb` (paradigm; ADR-0007). The pre-v2 `dbTable`/`dbView` subtypes are RETIRED — `source.rdb` + `@kind: table|view|materializedView|storedProc|tableFunction` is the form, with read-only-ness derived from `@kind`. Multi-source via `@role` (exactly one `primary` per object). Source physical name = `@table` (NOT `@name`); field physical name = `@column` (renamed from `@dbColumn`). Referential actions on relationships: `@onDelete` / `@onUpdate`.
-- Origin subtypes: `passthrough`, `aggregate`
+- Origin subtypes: `passthrough`, `aggregate`, `collection`, `computed`, `first` (concrete; `base` is the abstract root). `passthrough` is legal on an `object.value`-hosted field (FR-015 parameter lineage); the four assembly origins (`aggregate`/`computed`/`collection`/`first`) live on `object.projection` only — a value-hosted assembly origin is `ERR_SUBTYPE_RULE_VIOLATION` (#210).
 - Relationship subtypes: `association`, `aggregation`, `composition`. Cardinality via `@cardinality: one|many`; target via `@objectRef`. **M:N (FR-018) slim vocabulary:** `@cardinality: "many"` + `@objectRef` (target) + `@through` (the junction/through entity — a third entity that MUST declare two `identity.reference` children, one per FK side). The relationship's FK fields are **derived** from those references (the `identity.reference` SSOT for FK direction), never restated. `@sourceRefField` (optional) disambiguates a *directed* self-join by naming the source-side FK field on the junction (the other reference is the target side). `@symmetric` (optional boolean) marks an *undirected* self-join (union-on-read) — valid only when `@objectRef` == the declaring entity, and mutually exclusive with `@sourceRefField`. The pre-FR-018 `@joinEntity`/`@joinFields` attrs are REMOVED. Validation errors: symmetric-on-hetero / symmetric+sourceRefField → `ERR_BAD_ATTR_VALUE`; junction-missing-two-references / sourceRefField-not-matching / M:N-attr-on-1:N → `ERR_INVALID_RELATIONSHIP`.
 - Index subtypes: `index.lookup` (non-unique retrieval index; uniqueness is encoded in the **type**: `identity.secondary` = unique alternate key, `index.lookup` = non-unique; `@unique` is REMOVED from `identity.secondary` — `ERR_UNKNOWN_ATTR` on any legacy `@unique`). RDB-physical escapes `@using`/`@expr`/`@where`/`@orders` are registered by the db provider on **both** `identity.secondary` and `index.lookup`. `index.fulltext` / `index.vector` / `index.spatial` are reserved on the subtype axis — documented, NOT registered (YAGNI + 1.0 vocab freeze). See [ADR-0040](spec/decisions/ADR-0040-index-type-and-secondary-key-purity.md).
 - Layout subtypes: `dataGrid`