feat: implement MeshLoader

This loader abstracts mesh loading logic into a series of individual file handlers. Each handler is chosen based on the extension of the file to be loaded.

Cargo.toml

@@ -14,3 +14,6 @@ nalgebra = "*"
 uuid = { version = "1.23.1", features = ["v4"] }
 postcard = { version = "1.1", features = ["alloc"] }
 serde_json = "1.0.149"
+anyhow = "1.0.104"
+thiserror = "2.0.19"
+log = "0.4.29"