feat: nix support for the nix folks (#3924)

Co-authored-by: opencode <opencode@sst.dev>
Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>

nix/node-modules.nix

@@ -0,0 +1,52 @@
+{ hash, lib, stdenvNoCC, bun, cacert, curl }:
+args:
+stdenvNoCC.mkDerivation {
+  pname = "opencode-node_modules";
+  version = args.version;
+  src = args.src;
+
+  impureEnvVars =
+    lib.fetchers.proxyImpureEnvVars
+    ++ [
+      "GIT_PROXY_COMMAND"
+      "SOCKS_SERVER"
+    ];
+
+  nativeBuildInputs = [ bun cacert curl ];
+
+  dontConfigure = true;
+
+  buildPhase = ''
+    runHook preBuild
+    export HOME=$(mktemp -d)
+    export BUN_INSTALL_CACHE_DIR=$(mktemp -d)
+    bun install \
+      --cpu="*" \
+      --os="*" \
+      --frozen-lockfile \
+      --ignore-scripts \
+      --no-progress \
+      --linker=isolated
+    bun --bun ${args.canonicalizeScript}
+    bun --bun ${args.normalizeBinsScript}
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out
+    while IFS= read -r dir; do
+      rel="''${dir#./}"
+      dest="$out/$rel"
+      mkdir -p "$(dirname "$dest")"
+      cp -R "$dir" "$dest"
+    done < <(find . -type d -name node_modules -prune | sort)
+    runHook postInstall
+  '';
+
+  dontFixup = true;
+
+  outputHashAlgo = "sha256";
+  outputHashMode = "recursive";
+  outputHash = hash;
+}