Streaming SOG loading updates

[slimbuck]

This PR:

• waits for streaming SOG loading to settle before invoking first frame
• hide annotations in noui mode

[Copilot]

Pull request overview

This PR enhances streaming SOG (Gaussian Splat) loading in unified rendering mode and adds support for hiding annotations in noui mode. The changes ensure proper frame rendering synchronization by waiting for streaming data to settle before invoking the first frame event.

Key changes:

• Implements event-driven waiting for streaming SOG loading to complete before firing the first frame event
• Conditionally creates annotations only when UI is enabled (!config.noui)
• Adds forced rendering during streaming load to ensure unified rendering updates

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[mvaligursky]

• waits for streaming SOG loading to settle before invoking first frame

Cannot say I like this. In a way it removed part of reason for streaming LODs if we need to wait for all of that to be loaded.

[mvaligursky]

Maybe initially it should use low quality lod range (say the bottom 2 LODs). When those are loaded, start rendering, but enable further LODs?

[slimbuck]

Sure we can consider all this later along with reveal effects later.

[mvaligursky]

seems ok, but as mention in comment before, this needs further work before release.