fix(code-rs/nix): vendor git dependencies

code-rs/default.nix

@@ -9,9 +9,19 @@ rec {
     inherit env;
     pname = "code-rs";
     version = "0.1.0";
-    cargoLock.lockFile = ./Cargo.lock;
+    cargoLock = {
+      lockFile = ./Cargo.lock;
+      outputHashes = {
+        "mcp-types-0.0.0" = "sha256-BGpEuNXky7neVIQQHqyqRjoa/wemfp6zj+usJlkRN+g=";
+        "ratatui-0.29.0" = "sha256-HBvT5c8GsiCxMffNjJGLmHnvG77A6cqEL+1ARurBXho=";
+      };
+    };
     doCheck = false;
-    src = ./.;
+    # The workspace depends on crates from ../codex-rs, so provide the
+    # entire monorepo as the source and point the builder back to this
+    # package's directory.
+    src = ../.;
+    sourceRoot = "${baseNameOf ../.}/${baseNameOf ./.}";
     nativeBuildInputs = with pkgs; [
       pkg-config
       openssl