refactor(ariadne): use monorepo Rust layout

src/ariadne/BUILD

@@ -3,13 +3,13 @@ load("@rules_rust//rust:defs.bzl", "rust_binary", "rust_library")
 rust_library(
     name = "ariadne_lib",
     crate_name = "ariadne",
-    srcs = ["src/lib.rs"],
+    srcs = ["lib.rs"],
 )
 
 rust_binary(
     name = "ariadne",
     crate_name = "ariadne_cli",
-    srcs = ["src/main.rs"],
+    srcs = ["main.rs"],
     deps = [
         ":ariadne_lib",
         "//third_party/crates:clap",

src/ariadne/Cargo.toml

@@ -3,6 +3,13 @@ name = "ariadne"
 version = "0.1.0"
 edition = "2024"
 
+[lib]
+path = "lib.rs"
+
+[[bin]]
+name = "ariadne"
+path = "main.rs"
+
 [dependencies]
 clap = { version = "4", features = ["derive"] }
 serde = { version = "1.0", features = ["derive"] }