Add project scaffolding

Makefile, Dockerfile, CI workflow, prettier config, manifests for
Chrome (MV3) and Firefox (MV2), source directory structure, and
minimal test suite. All checks pass.

package.json

@@ -0,0 +1,20 @@
+{
+    "name": "autistmask",
+    "version": "0.1.0",
+    "description": "Minimal Ethereum wallet browser extension for Chrome and Firefox",
+    "author": "sneak <sneak@sneak.berlin>",
+    "license": "GPL-3.0",
+    "private": true,
+    "scripts": {
+        "test": "jest --forceExit",
+        "build": "node build.js",
+        "lint": "prettier --check .",
+        "fmt": "prettier --write .",
+        "fmt-check": "prettier --check ."
+    },
+    "devDependencies": {
+        "jest": "^30.2.0",
+        "prettier": "^3.8.1"
+    },
+    "dependencies": {}
+}