Docs: union sources document a per-source index: key that FindManyUnionSource does not have (TS2353) #385

Summary

The pagination docs show a per-source index: { name, range } key inside union() sources. FindManyUnionSource has no such key — it exposes only where. Copying the documented example fails typecheck with TS2353.

Root cause

packages/kitcn/src/orm/types.ts:70-74:

export type FindManyUnionSource<
  TTableConfig extends TableRelationalConfig = TableRelationalConfig,
> = {
  where?: RelationsFilter<TTableConfig, any> | WhereCallback<TTableConfig>;
};

The docs show otherwise:

• www/content/docs/orm/queries/pagination.mdx:139 and :145
• packages/kitcn/skills/kitcn/references/features/orm.md:569 and :575

Both render a union source containing an index: block.

Impact

• A user following the documented example gets TS2353: Object literal may only specify known properties, and 'index' does not exist in type 'FindManyUnionSource'.
• The error is at least loud — the type system rejects it rather than silently ignoring it at runtime — so this is a documentation defect, not a data-correctness hazard.
• The two doc surfaces are required to stay in sync (AGENTS.md: docs sync), so both need the same edit.

Suggested fix

Two options, and the choice depends on planned work:

1. Correct the docs now — remove the index: block from both examples so they describe the shipped API.
2. Implement the documented shape — add per-source index: { name, range } to FindManyUnionSource and honour it in _buildUnionSourceStream.

Option 2 is separately desirable (union sources currently cannot be index-anchored at all, so each source re-walks the shared index), but it is a larger change. If it is not imminent, do option 1 now rather than leaving the docs wrong.

Environment

• kitcn 0.25.7
• convex 1.44.0
• verified at commit 471ec753