Add GitHub Codespaces devcontainer configuration

Co-authored-by: KSXGitHub <11488886+KSXGitHub@users.noreply.github.com>

Author: Copilot

.devcontainer/devcontainer.json

@@ -0,0 +1,30 @@
+{
+  "name": "parallel-disk-usage",
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "features": {
+    "ghcr.io/devcontainers/features/rust:1": {
+      "version": "none",
+      "profile": "default"
+    },
+    "ghcr.io/devcontainers/features/node:1": {
+      "version": "lts",
+      "nodeGypDependencies": true
+    },
+    "ghcr.io/devcontainers/features/python:1": {
+      "version": "latest",
+      "installTools": true
+    },
+    "ghcr.io/devcontainers-contrib/features/shellcheck:1": {},
+    "ghcr.io/devcontainers-contrib/features/shfmt:1": {}
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "rust-lang.rust-analyzer",
+        "timonwong.shellcheck",
+        "mkhl.shfmt"
+      ]
+    }
+  },
+  "postCreateCommand": "bash .devcontainer/post-create.sh"
+}

.devcontainer/post-create.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Install Python dependencies
+pip install toml
+
+# Install pnpm and project Node dependencies
+npm install -g pnpm
+(cd ci/github-actions && pnpm install)
+
+# Install hyperfine via Cargo
+cargo install hyperfine