Improve movement, crouching, and add M2 animation

Movement:
- Fix speed controls: Shift=sprint (28), normal run (14), Ctrl=walk (5)
- Reduce character height for doorway clearance (eye height 1.2)
- Add working crouch (C or X key) with smooth transition (eye height 0.6)
- Jump to stand up from crouch

M2 Animation:
- Add animation time tracking per M2 instance
- Add procedural swaying animation in vertex shader
- Update animation each frame for vegetation movement

src/rendering/renderer.cpp

@@ -569,6 +569,11 @@ void Renderer::update(float deltaTime) {
         characterRenderer->update(deltaTime);
     }
 
+    // Update M2 doodad animations
+    if (m2Renderer) {
+        m2Renderer->update(deltaTime);
+    }
+
     // Update zone detection and music
     if (zoneManager && musicManager && terrainManager && camera) {
         // First check tile-based zone