capsite/lib: MapStore and patterns work-alikes

Enough of @agoric/store's MapStore and @endo/patterns' M for the
credential-rotation design: makeMapStore(label, { keyShape, valueShape },
kv) keeps entries in a DO's sync KV under store:<label>:, and readOnly()
hands out the queries alone. Facets are workerd RpcTargets in place of
endo's Far.

Unlike endo, error messages never include keys or values: the values
here are credentials, and messages cross RPC into logs.

Generated-by: Claude Opus 5.5

lib/tsconfig.json

@@ -0,0 +1,15 @@
+{
+	"compilerOptions": {
+		"target": "ES2022",
+		"module": "preserve",
+		"moduleResolution": "bundler",
+		"strict": true,
+		"esModuleInterop": true,
+		"verbatimModuleSyntax": true,
+		"skipLibCheck": true,
+		"lib": ["ES2022", "ESNext.Disposable"],
+		"noEmit": true,
+		"types": []
+	},
+	"include": ["src/**/*", "worker-configuration.d.ts"]
+}