Add SiK Radio Tools to WebTools hub (Web Serial, client-side)

I’d like to contribute SiK Radio Tools, a browser-based configurator for SiK telemetry radios (900 MHz / 433 MHz), as a new tool under the [WebTools](https://github.com/ArduPilot/WebTools) repo so it can appear on the public hub (e.g. [firmware.ardupilot.org/Tools/WebTools/](https://firmware.ardupilot.org/Tools/WebTools/)).

The app uses the Web Serial API (currently tested in chrome browser) to talk to radios over USB. All processing stays in the browser. No log or parameter data is uploaded to a server, consistent with the existing WebTools privacy model.

Upstream source: https://github.com/JamesM9/SIK-Radio-Tools

**What the tool does**
Connect to a SiK radio over USB (Web Serial), configurable baud (default 57600).
Load/save radio parameters, terminal (AT commands), diagnostics, profiles, optional firmware .hex flash via bootloader—client-side only.

**Questions for maintainers**
Folder name — Preferred naming convention? (e.g. SiKRadioTools vs SiKRadio vs other.)
Hub placement — Should this sit in the main tool list, or under [Dev](https://github.com/ArduPilot/WebTools/tree/main/Dev) (WIP) until reviewed?

If this direction sounds reasonable, I’ll open a PR that adds the tool folder + hub row, with local test notes (python -m http.server from repo root).

Thanks for considering it.

Review the upstream SiK-Radio-Tools project and the WebTools hub before deciding the folder name and whether placement belongs in the main list or Dev. Run `python -m http.server` from the repository root to check local serving. Done means the tool folder and hub row are added and the browser-based tool can be verified locally.

Written by the indexing model from the issue text.