docs(changelog): record the toolchain update

[paustint]

Adds an [Unreleased] entry for the dev dependency update in #7, so there is something to release. It derives a patch: 0.1.0 -> 0.1.1.

#7 only touched tooling, docs and lockfiles, so the changelog check correctly didn't require an entry.

• There are no runtime dependency changes.
• dist built from main is byte-identical to the published 0.1.0 package.
• 0.1.1 will be the first version of this package published from the CI release workflow, and the first with npm provenance. 0.1.0 was published locally.

npm run release -- --dry-run output:

  0.1.0 -> 0.1.1
  patch derived from ### Changed

[Copilot]

Copilot review overview

🟢 Approval recommended

No unresolved issues were identified.

Review effort: Lite
Findings: None

What changed in this PR

Documents the development toolchain update in the unreleased changelog and supports the 0.1.1 patch release.

Changes:

• Records updated development dependencies and tooling.
• Notes unchanged runtime dependencies and published bundles.

File	Description
CHANGELOG.md	Adds the unreleased toolchain update entry.

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