Bump package version to 2.6.0

[Copilot]

Prepares the 2.6.0 release by updating the package version on the main release line. This keeps the published package metadata and exported runtime version aligned.

• Version metadata

  • Update package.json version to 2.6.0
  • Update both package-lock.json version entries to 2.6.0

• Runtime version constant

  • Update src/version.ts so the exported SDK version matches the package metadata

export const VERSION = "2.6.0";

Original prompt

Please create a version bump PR for version 2.6.0 targeting the main branch. Update the version in src/version.ts, package.json, and package-lock.json.