docs(metadata): README no longer says ViewMetadata is unknown

The TypeScriptSerializer paragraph gave "its ViewMetadata type is unknown"
as the reason a saved view is written with no annotation. This branch
narrows ViewMetadata to the union of the input types of the members
ViewMetadataSchema's union runs, so that parenthetical is false, and
README.md ships in the @objectstack/metadata tarball. The clause now says
what the serializer comment says: the schema's z.input is unknown, and
ViewMetadata is declared as that member union instead, so it is not the
bound schema's z.input type.

Claude-Session: https://claude.ai/code/session_019c3Hi6ZMU1p6m6aA6Bz45d
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/metadata/README.md

@@ -74,7 +74,7 @@ Serializers convert metadata objects to/from different file formats:
 
 - **JSONSerializer** — `.json` files with optional key sorting
 - **YAMLSerializer** — `.yaml`/`.yml` files (JSON_SCHEMA for security)
-- **TypeScriptSerializer** — the `typescript` / `javascript` formats (`.ts` / `.js`): a JSON document wrapped in a module, the file format `FilesystemLoader` writes and reads for those two formats (`typescript` is `FilesystemLoader.save()`'s default, so `MetadataManager.save()` routed to the filesystem loader writes `{rootDir}/{type}/{name}.ts`). It writes `export const metadata = { …JSON… };` then `export default metadata;`. A `typescript`-format file that `FilesystemLoader.save()` writes with the built-in serializer the package wires in also annotates that constant with the spec type of the item's metadata type, and imports it: `ServiceObject` from `@objectstack/spec/data` for an `object`, `Flow` from `@objectstack/spec/automation` for a `flow`, and so on. Each is exactly the `z.input` type of the schema `getMetadataTypeSchema()` resolves for that metadata type. A metadata type with no such spec type is written with no annotation and no import: `view` (its `ViewMetadata` type is `unknown`), `book`, `external_catalog`, or a plugin's own type. Only the loader knows the metadata type, so it picks the annotation through a package-internal function, and `TypeScriptSerializer.serialize()` called directly writes no annotation. A serializer wired in by hand (a custom one, a subclass that overrides `serialize()`, or a `TypeScriptSerializer` from the package's other entry point) is called through its own `serialize()`. It reads back the first `{ … }` block after the first `export const` (or, failing that, `export default`), which must be JSON: double-quoted keys and strings, no comments, no trailing commas, no functions. It is **not** an authoring shape: authored metadata such as a `*.object.ts` is written `ObjectSchema.create({ … })` (or `defineView()`, …), which this serializer never emits, and an authored file with unquoted keys is refused rather than read.
+- **TypeScriptSerializer** — the `typescript` / `javascript` formats (`.ts` / `.js`): a JSON document wrapped in a module, the file format `FilesystemLoader` writes and reads for those two formats (`typescript` is `FilesystemLoader.save()`'s default, so `MetadataManager.save()` routed to the filesystem loader writes `{rootDir}/{type}/{name}.ts`). It writes `export const metadata = { …JSON… };` then `export default metadata;`. A `typescript`-format file that `FilesystemLoader.save()` writes with the built-in serializer the package wires in also annotates that constant with the spec type of the item's metadata type, and imports it: `ServiceObject` from `@objectstack/spec/data` for an `object`, `Flow` from `@objectstack/spec/automation` for a `flow`, and so on. Each is exactly the `z.input` type of the schema `getMetadataTypeSchema()` resolves for that metadata type. A metadata type with no such spec type is written with no annotation and no import: `view` (`ViewMetadataSchema` is a `z.preprocess`, whose `z.input` type is `unknown`; `ViewMetadata` is declared instead as the union of the input types of the members that schema's union runs, so it is not that schema's `z.input` type), `book`, `external_catalog`, or a plugin's own type. Only the loader knows the metadata type, so it picks the annotation through a package-internal function, and `TypeScriptSerializer.serialize()` called directly writes no annotation. A serializer wired in by hand (a custom one, a subclass that overrides `serialize()`, or a `TypeScriptSerializer` from the package's other entry point) is called through its own `serialize()`. It reads back the first `{ … }` block after the first `export const` (or, failing that, `export default`), which must be JSON: double-quoted keys and strings, no comments, no trailing commas, no functions. It is **not** an authoring shape: authored metadata such as a `*.object.ts` is written `ObjectSchema.create({ … })` (or `defineView()`, …), which this serializer never emits, and an authored file with unquoted keys is refused rather than read.
 
 ### 4. Overlay / Customization System