Vendor helgoboss/helgobox (ReaLearn) as basis for custom UI fork

Stripped upstream git history; starting point for replacing the native
SWELL/Win32 mapping UI with something more suited to bulk editing.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

plugin-reaper-realearn/artwork-processor/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "helgobox-artwork-processor"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+resvg = { workspace = true, features = ["system-fonts"] }
+anyhow.workspace = true
+
+[lints.clippy]
+enum_glob_use = "deny"