Performance optimizations and collision improvements

Performance:
- Remove expensive inverse() from all vertex shaders (terrain, WMO, M2, water, character)
- Add uniform location caching to avoid repeated glGetUniformLocation calls
- Add proper frustum culling for WMO groups using AABB intersection
- Add distance-based culling for WMO and M2 instances
- Add cleanup of unused M2/WMO models when tiles unload

Collision & Movement:
- Add M2 doodad collision detection (fences, boxes, etc.)
- Reduce character eye height (5.0 -> 1.8) and collision radius (2.5 -> 0.5)
- Enable WoW-style movement speed by default (14 units/sec run, 5 walk, 9 back)
- Fix emote grammar ("You waves." -> "You wave.")

Misc:
- Rename window title to "Wowee"

src/ui/game_screen.cpp

@@ -548,7 +548,7 @@ void GameScreen::sendChatMessage(game::GameHandler& gameHandler) {
                         chatText = emoteText;
                     }
                 } else {
-                    chatText = emoteText;
+                    chatText = command + ".";  // First person: "You wave."
                 }
 
                 // Add local chat message