fix: require https for external pricing providers

Require HTTPS-only external pricing-provider URLs and verify the adapter contract with the application suite.

apps/api/src/modules/pricing/providers/http-pricing-provider.js

@@ -10,10 +10,21 @@ export function createHttpPricingProvider({
     throw new Error('Pricing provider endpoint is required.');
   }
 
+  let parsedUrl;
+  try {
+    parsedUrl = new URL(endpoint);
+  } catch {
+    throw new Error('Pricing provider endpoint must be a valid HTTPS URL.');
+  }
+
+  if (parsedUrl.protocol !== 'https:') {
+    throw new Error('Pricing provider endpoint must use HTTPS.');
+  }
+
   return createPricingProvider({
     id,
     async observe(input) {
-      const url = new URL(endpoint);
+      const url = new URL(parsedUrl.toString());
       for (const [key, value] of Object.entries(input)) {
         if (value) url.searchParams.set(key, value);
       }

apps/api/tests/application/pricing-provider.test.js

@@ -58,6 +58,26 @@ test("fixture provider returns deterministic normalized observations", async ()
   });
 });
 
+test("http provider rejects insecure or malformed external provider URLs", () => {
+  assert.throws(
+    () =>
+      createHttpPricingProvider({
+        id: "http-provider",
+        endpoint: "http://provider.example/prices",
+      }),
+    /HTTPS/i,
+  );
+
+  assert.throws(
+    () =>
+      createHttpPricingProvider({
+        id: "http-provider",
+        endpoint: "not-a-url",
+      }),
+    /valid https URL/i,
+  );
+});
+
 test("http provider sends mapping context and normalizes its response", async () => {
   let request;
   const provider = createHttpPricingProvider({