GSplat double click and sogs support

[slimbuck]

This PR:

• updates to the latest engine version
• supports loading sogs scenes
• use picker to implement double-click to focus that works for meshes and gplats
• tweak camera:
  • R to reset camera to world center (like supersplat and supersplat-viewer)
  • base fly speed on orbit camera zoom

[Copilot]

Pull Request Overview

This PR updates the engine to the latest version, adds support for SOGS scenes, and implements double-click focus functionality for meshes and GSplats using a new picker implementation. Key changes include replacing the old depth-reading approach with a new Picker class, updating camera controls (including resetting via the R key and adjusting fly speed), and removing the deprecated read-depth module.

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/viewer.ts	Updates to camera control, double-click focus via picker, and enhancements to loadPly to support external URLs
src/read-depth.ts	Removal of the deprecated depth reading implementation
src/picker.ts	Addition of a new Picker class for handling picking logic
src/multiframe.ts	Type adjustments to use GraphicsDevice instead of WebglGraphicsDevice
src/index.tsx	Minor cleanup (removed extraneous whitespace)

Files not reviewed (1)

• package.json: Language not supported

Comments suppressed due to low confidence (1)

src/viewer.ts:1163

• [nitpick] Consider using a properly typed object or a Map instead of 'any' for holding external URL mappings to improve type safety and code clarity.

const urls: any = {};