feat(wan): Add Wan2.2 I2V support

mlx_video/convert_wan.py

@@ -338,6 +338,10 @@ def convert_wan_checkpoint(
             print(f"  Source config: dim={src_dim}, layers={src_num_layers}, "
                   f"heads={src_num_heads}, type={src_model_type}")
 
+            # Use preset for known TI2V 5B configuration
+            if src_model_type == "ti2v" and src_dim == 3072:
+                return WanModelConfig.wan22_ti2v_5b()
+
             is_22 = model_version == "2.2"
 
             # Wan2.2 uses different VAE with z_dim=48 and stride (4,16,16)
@@ -409,7 +413,8 @@ def convert_wan_checkpoint(
         weights = load_torch_weights(str(vae_path))
         if is_wan22_vae:
             from mlx_video.models.wan.vae22 import sanitize_wan22_vae_weights
-            weights = sanitize_wan22_vae_weights(weights)
+            include_encoder = config.model_type == "ti2v"
+            weights = sanitize_wan22_vae_weights(weights, include_encoder=include_encoder)
         else:
             weights = sanitize_wan_vae_weights(weights)
         # Always save VAE in float32 — official Wan2.2 runs VAE decode in