Add overview repo and verae-nats-process expansion template

High-level system map with diagrams, TOC, and a docs index. Template
worker shows how to add a new verae.* address for search, storage, or
unplanned functions without teaching Zapier NATS.

packages/verae-nats-process/src/handle.js

@@ -0,0 +1,20 @@
+/**
+ * Replace this with search, store, or any new function.
+ * Must be idempotent: the same correlationId may be redelivered.
+ *
+ * @param {object} msg
+ * @returns {Promise<object>|object}
+ */
+export function handle(msg = {}) {
+  const correlationId = msg.correlationId || msg.traceId;
+  if (!correlationId) {
+    throw new Error('correlationId or traceId is required');
+  }
+  return {
+    ok: true,
+    correlationId,
+    echo: msg.payload ?? msg,
+    processedAt: new Date().toISOString(),
+    note: 'Template handler — replace handle() in src/handle.js',
+  };
+}