Fix effect-schema $type output inference

[danieljvdm]

effect-schema picked the runtime schema from the SQL column kind, but it dropped TColumn["_"]["data"] from the exposed Effect type. In emitted consumer types that could widen .$type<>() overrides back to the base schema output, and a plain Schema<TData, ...> rewrite also risked erasing schema-specific surface.

Broken:

type MyBrandedId = string & Brand.Brand<"MyBrandedId">;
type Foo = s.Schema.Type<typeof s.Literal("Foo")>;

const table = pgTable("test", {
  id: uuid().$type<MyBrandedId>().notNull(),
  value: varchar().$type<Foo>().notNull(),
});

const result = createSelectSchema(table);
// Schema.Type<typeof result>["id"] was string
// Schema.Type<typeof result.fields.id> could also widen unexpectedly
// Schema.Context<typeof result.fields.id> needed to stay never

Now working:

type RebuildEffectSchema<TSchema extends Schema.Any, TData> =
  Omit<TSchema, keyof Schema.Any> &
  Schema<TData, s.Schema.Encoded<TSchema>, s.Schema.Context<TSchema>>;

GetEffectSchemaType now captures TData once at the export boundary and applies the override by rebuilding the schema structurally, so it preserves the original schema surface while replacing only the exposed output type.

Also added PG validator assertions for:

• Schema.Type<typeof result>[...]
• Schema.Type<typeof result.fields....>
• Schema.Context<typeof result>
• Schema.Context<typeof result.fields....>