feat(nodejs): protocol version option, binary protocol for doubles

[glasstiger]

Support for sending doubles as binary, and resolving the protocol version option.

[Copilot]

Pull Request Overview

This PR introduces support for protocol version negotiation and binary serialization of double values in the QuestDB Node.js client. The main changes include making configuration parsing asynchronous to support HTTP endpoint queries, adding a new binary protocol (version 2) for more efficient double encoding, and restructuring the buffer implementation with version-specific classes.

• Adds protocol_version configuration option with support for 'auto', '1', and '2' values
• Implements binary serialization for doubles in protocol version 2 vs text serialization in version 1
• Makes Sender.fromConfig() and SenderOptions.fromConfig() async to support server version negotiation

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
test/util/mockhttp.ts	Adds settings endpoint mock and protocol version configuration support
test/sender.transport.test.ts	Updates all test calls to use async Sender.fromConfig and adds protocol_version parameters
test/sender.integration.test.ts	Converts Sender constructor calls to use SenderOptions.resolveAuto for proper version resolution
test/sender.config.test.ts	Updates configuration tests to be async and adds protocol_version to all test cases
test/sender.buffer.test.ts	Adds protocol_version parameter to all Sender constructor calls in tests
test/options.test.ts	Extensive updates to test protocol version parsing, validation, and HTTP endpoint negotiation
src/utils.ts	Adds fetchJson utility function for HTTP requests
src/sender.ts	Makes fromConfig and fromEnv methods async, changes buffer creation to use factory pattern
src/options.ts	Adds protocol version parsing, validation, and automatic resolution via HTTP settings endpoint
src/buffer/index.ts	Refactors to interface-based design with factory function for version-specific buffer creation
src/buffer/bufferv2.ts	Implements binary double serialization for protocol version 2
src/buffer/bufferv1.ts	Implements text-based serialization for protocol version 1 (existing behavior)
src/buffer/base.ts	Moves common buffer functionality to abstract base class