Document UUID → UInt128 insert patterns with round-trip assertion

[Copilot]

Inserting a UUID string into a UInt128 column via JSONEachRow fails with CANNOT_PARSE_INPUT_ASSERTION_FAILED because ClickHouse only converts UUID → UInt128 implicitly for the VALUES clause. The client correctly forwards the JSON unchanged; users need guidance on the supported patterns.

Summary

Adds a new example (Node + Web) demonstrating two working approaches, with a round-trip assertion proving the server stores the value byte-for-byte.

• examples/{node,web}/coding/insert_uuid_into_uint128.ts — two patterns:
  • Client-side conversion (recommended): BigInt('0x' + uuid.replace(/-/g, '')).toString() passed as the UInt128 column value.
  • EPHEMERAL UUID column: UInt128 DEFAULT id_uuid + UUID EPHEMERAL paired with insert({ columns: ['id_uuid', ...] }).
• Round-trip assertion after each SELECT (node:assert/strict in Node; tiny inline assertEqual in Web, since node:assert isn't browser-compatible). Both patterns produce the same UInt128 decimal 2126302229887840375125392584261985180.
• examples/README.md — new row in the coding/ table.

function uuidToUInt128(uuid: string): string {
  return BigInt('0x' + uuid.replace(/-/g, '')).toString()
}

await client.insert({
  table,
  values: [{ id: uuidToUInt128(uuid), description: '...' }],
  format: 'JSONEachRow',
})

Checklist

• A human-readable description of the changes was provided to include in CHANGELOG

Release note

Added examples/{node,web}/coding/insert_uuid_into_uint128.ts showing how to insert a UUID into a UInt128 column with JSONEachRow, either via client-side BigInt conversion or via an EPHEMERAL UUID column with a UInt128 DEFAULT expression, with a round-trip assertion verifying the stored value.

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[Copilot]

Pull request overview

Adds Node and Web examples documenting how to insert UUID-derived values into UInt128 columns through JSON formats, including assertions that both supported patterns round-trip to the same stored value.

Changes:

• Adds client-side UUID-to-UInt128 conversion examples for Node and Web.
• Adds EPHEMERAL UUID column + UInt128 DEFAULT examples for Node and Web.
• Adds the new example pair to the examples README coding table.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
examples/node/coding/insert_uuid_into_uint128.ts	Adds the Node example with node:assert round-trip checks.
examples/web/coding/insert_uuid_into_uint128.ts	Adds the Web example with an inline assertion helper.
examples/README.md	Links the new Node and Web examples in the coding section.