Add wp-env, Codespaces, and WordPress Playground support

Add a basic wp-env configuration for local development, a devcontainer
for GitHub Codespaces support, and a WordPress Playground blueprint for
quick browser-based testing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: claude

.devcontainer/devcontainer.json

@@ -0,0 +1,15 @@
+{
+	"name": "Theme Image Block",
+	"image": "mcr.microsoft.com/devcontainers/javascript-node:22",
+	"features": {
+		"ghcr.io/devcontainers/features/docker-in-docker:2": {}
+	},
+	"postCreateCommand": "npm install",
+	"forwardPorts": [8888],
+	"portsAttributes": {
+		"8888": {
+			"label": "WordPress",
+			"onAutoForward": "notify"
+		}
+	}
+}

.wp-env.json

@@ -0,0 +1,12 @@
+{
+	"core": "WordPress/WordPress#6.9",
+	"phpVersion": "8.2",
+	"plugins": [
+		"."
+	],
+	"config": {
+		"WP_DEBUG": true,
+		"WP_DEBUG_LOG": true,
+		"SCRIPT_DEBUG": true
+	}
+}

blueprint.json

@@ -0,0 +1,19 @@
+{
+	"landingPage": "/wp-admin/post-new.php",
+	"preferredVersions": {
+		"php": "8.2",
+		"wp": "latest"
+	},
+	"steps": [
+		{
+			"step": "installPlugin",
+			"pluginData": {
+				"resource": "wordpress.org/plugins",
+				"slug": "theme-image-block"
+			}
+		},
+		{
+			"step": "login"
+		}
+	]
+}

package.json

@@ -33,14 +33,20 @@
     "copy-webpack-plugin": "^13.0.1",
     "npm-package-json-lint": "^9.1.0",
     "webpack": "^5.105.2",
+    "@wordpress/env": "^10.0.0",
     "webpack-cli": "^6.0.1"
   },
   "scripts": {
     "build": "webpack --mode production",
     "start": "webpack --mode development --watch",
     "lint": "eslint ./blocks/src",
     "fix": "eslint ./blocks/src --fix",
-    "lint:package": "node ./node_modules/npm-package-json-lint/dist/cli.js ./"
+    "lint:package": "node ./node_modules/npm-package-json-lint/dist/cli.js ./",
+    "env:start": "wp-env start",
+    "env:stop": "wp-env stop",
+    "env:destroy": "wp-env destroy",
+    "env:cli": "wp-env run cli",
+    "env:logs": "wp-env logs"
   },
   "npmpackagejsonlint": {
     "extends": "@wordpress/npm-package-json-lint-config"