chore: preserve initial reconstruction prototype

lib/config.js

@@ -0,0 +1,30 @@
+import { z } from "zod";
+
+const envSchema = z.object({
+  OLLAMA_BASE_URL: z.string().url(),
+  OLLAMA_MODEL: z.string().min(1),
+});
+
+export function getConfig() {
+  const parsed = envSchema.safeParse({
+    OLLAMA_BASE_URL: process.env.OLLAMA_BASE_URL,
+    OLLAMA_MODEL: process.env.OLLAMA_MODEL,
+  });
+
+  if (!parsed.success) {
+    return { ok: false, error: parsed.error.flatten().fieldErrors };
+  }
+
+  return { ok: true, config: parsed.data };
+}
+
+export function assertConfig() {
+  const result = getConfig();
+  if (!result.ok) {
+    throw new Error(
+      "Invalid configuration:\n" +
+        Object.entries(result.error).map(([k, v]) => `  ${k}: ${v}`).join("\n")
+    );
+  }
+  return result.config;
+}