Chat Tabs

### Changes

* Sound notifications for incoming whispers — multiple sounds (Pling, Bell, Chime, Xylophone, Cow Bell, Bit, Amethyst, XP Orb, Level Up, Challenge), volume slider, and on/off toggle

* Click-to-expand unread badge (✉) — expands into a list of unread conversations; click a name to open that tab

* Whisper cooldown — configurable delay (0–60 s, default 3 s) between private sends, with on-screen cooldown indicator

* Settings GUI reorganized into tabs: **Appearance**, **Persistence**, **Private**

* Expanded Minecraft version support (1.21.1, 1.21.3–1.21.6, 1.21.8, 1.21.9, 1.21.11, 26.1.x, 26.2, 26.3)

### Bug fixes / improvements

* Separated private tabs from the general chat HUD (dedicated buffering/rendering) — no lag when switching or viewing private conversations

* Private-tab whisper command prefill

* Pressing enter in private tab doesn't close window now

* Closing chat window always bring you back to general tab

* Chat notifications from other mods are not rendered in private tabs anymore, instead all go to general tab

* Chat history cap handling cleaned up

* Code cleanup, remap fixes, Stonecutter upgrade

**Full Changelog**: https://github.com/Fractal420/Chat-Tabs-Mod/compare/1.0.4...1.0.5