Sync lib_ui with Telegram Desktop 7.0.5

[Suoriks]

This pull request was generated by AI.

What changed

• Updated the AyuGram lib_ui line to upstream desktop-app/lib_ui revision 07cea400e2e6b2a7c08a289472bf5976a77e6500, used by Telegram Desktop 7.0.5.
• Reapplied and adapted the AyuGram UI layer, including Ayu settings, font/material switches, avatar handling, quote styling, entity flags, and slide easing.
• Kept the upstream UI and accessibility changes required by the matching Telegram Desktop source tree.

Why

The Telegram Desktop 7.0.5 integration in AyuGramDesktop requires the current lib_ui API. Pointing the superproject at upstream directly removed Ayu-specific UI contracts, while keeping the previous Ayu commit did not provide the new Telegram interfaces. This branch combines both sides into one buildable tree.

Validation

• lib_ui.vcxproj compiled successfully as part of a clean Windows x64 Release build on ai-station.
• The dependent AyuGramDesktop build, link, unsigned installer packaging, isolated installation, and 12-second launch smoke test all completed with exit code 0.
• Tested installer SHA-256: CF00E988911075EC185FC6224965994B5AA1D7BF386B5C7D467847CE1A976DB1.
• The user manually tested the resulting installer and reported that everything appeared to work.

The corresponding AyuGramDesktop pull request will reference this dependency.