Menu Set store, image pipeline and Site config

The store keeps a Menu Set's state in the directory layout (drafts/ versus
published/) and its metadata in a manifest, with publishing as a single
directory rename. Editing is allowed on Drafts only, so a published menu can
never change under a customer. Stages 2 and 3 of docs/plan.md, with tests.

tsconfig.json

@@ -0,0 +1,22 @@
+{
+  "compilerOptions": {
+    "target": "es2024",
+    "lib": ["es2024"],
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "allowImportingTsExtensions": true,
+    "erasableSyntaxOnly": true,
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+    "strict": true,
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+    "noImplicitOverride": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "skipLibCheck": true,
+    "types": ["node"]
+  },
+  "include": ["src/**/*.ts", "test/**/*.ts"]
+}