Bump bun to 1.3.14 (#145)

Bumps Bun from `1.3.13` to `1.3.14`, updating the required engine version, dev dependencies, and lockfile accordingly.

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> [!NOTE]
> **Low Risk**
> Low risk dependency/tooling bump that primarily affects local/dev environments and CI; runtime behavior should be unchanged aside from any Bun 1.3.14 compatibility differences.
> 
> **Overview**
> Bumps the required Bun version to `1.3.14` across tooling (`mise.toml`) and `package.json` `engines`.
> 
> Updates Bun type dependencies (`@types/bun`/`bun-types`) and refreshes `bun.lock` accordingly.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit adbab75e962db5117226e0f46b1c46ee2e80ece0. Configure [here](https://www.cursor.com/dashboard/bugbot).</sup>
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