feat: image resizing (#5446)

Add image resizing on the client side to reduce load on the API

codex-rs/utils/image/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "codex-utils-image"
+version.workspace = true
+edition.workspace = true
+
+[lints]
+workspace = true
+
+[dependencies]
+base64 = { workspace = true }
+image = { workspace = true, features = ["jpeg", "png"] }
+codex-utils-cache = { workspace = true }
+thiserror = { workspace = true }
+tokio = { workspace = true, features = ["fs", "rt", "rt-multi-thread", "macros"] }
+
+[dev-dependencies]
+image = { workspace = true, features = ["jpeg", "png"] }
+tempfile = { workspace = true }