Center Gear panels over the full stage

[AUDOSt0ck1ng]

Summary

• make Appearance, Voice, Camera & Lighting, and Settings fill the avatar stage
• centre every panel and retain rounded floating-panel chrome
• document the shared panel behaviour and add an Unreleased changelog entry

Why

The previous narrow right-edge drawers felt visually asymmetric beside the full avatar stage. A consistent full-stage surface gives every Gear panel the same visual weight without expanding the desktop window beyond screen edges.

Testing

• npm run lint — passed
• Manual desktop UI check — passed by the requester
• npm test — 142 non-build tests passed; four Vite build probes could not run in the restricted local sandbox

Screenshots

Existing screenshots are unchanged in this PR. Maintainer guidance on whether the panel screenshots should be refreshed is welcome.

[AUDOSt0ck1ng]

@rosspeili
Please first confirm whether these changes are acceptable.

If so, I'd also like to make some layout adjustments and continue committing them to this PR.
Additionally, I'd also like to update the screenshots.

Demo:
https://www.youtube.com/shorts/G6ub-tyNsbU

[AUDOSt0ck1ng]

The main reasons for this adjustment are:

• Better UI design and presentation: A centered, symmetrical, and larger layout provides more space and flexibility for UI design.
• Maintain edge-device compatibility: The size is capped at the avatar rendering stage rather than scaling indefinitely, so it's supposed to work properly on edge devices.

[rosspeili]

Hey @AUDOSt0ck1ng, I somehow felt the old one is better as squared, and feels as a side bar than overlay. most of the things could fit nicely with scroll, and we had a minimal, slick, thin aesthetic. This looks a bit stretched. I am not against it, especially if you think it's best ui practice, but would redesign components, sizing, alignments etc a bit. eg. smaller buttons centered as they were, environments cards should be more squared / vertical as they were and centered instead of stretch to fit full size.

Other than that, I don't have a strong opinion and not a ui expert, so I'd follow you along if you think it's best practice. I can assume you do this to prepare for edge devices?

I would like to see your next commit and polish and layout adjustments you mentioned, and then we can check again and If you wound't mind I could contribute to it as well. Like add pop up and close animations to make it smooth, work on glassmorphism a bit, and as you said component layout and adjustments.

Other than that, I think this should move fwd. <3

[AUDOSt0ck1ng]

I’ll think about it for now. Until we have a concrete plan, let’s keep it as a draft.

[rosspeili]

@AUDOSt0ck1ng kk, let me think about it as well and contribute to your pr if you don't mind.

[AUDOSt0ck1ng]

Sure.

[AUDOSt0ck1ng]

@rosspeili
Since I'm not a professional designer, I make claude code to design:
https://claude.ai/code/artifact/eab53af1-1a08-45d0-9a2f-e67f50e9d1e9

I think it's great, how do you think?