Render: bounded PNG/JPEG texture input admission (#909)

Bounded in-memory PNG/JPEG texture decoding with explicit base-colour/data-map roles; RGBA8 pixels are published only after a complete decode. Input only: no material assignment, GPU shading or persistence. Refs #900.

Contributed by @0xlillith.

Co-authored-by: lillith <35337584+0xlillith@users.noreply.github.com>

crates/render/Cargo.toml

@@ -11,7 +11,7 @@ workspace = true
 [dependencies]
 solidcraft-geom = { workspace = true }
 serde = { workspace = true }
-image = { workspace = true }
+image = { workspace = true, features = ["jpeg"] }
 
 [dev-dependencies]
 serde_json = { workspace = true }