fix: require genuine live hosting evidence

scripts/verify-hosting-headers.mjs

@@ -1,5 +1,7 @@
 import { mkdir, readFile, readdir, writeFile } from "node:fs/promises";
 
+import { classifyLiveHostingBaseUrl } from "./lib/hosting-probe.mjs";
+
 const cachePolicy = JSON.parse(
   await readFile("config/hosting/cache-policy.json", "utf8"),
 );
@@ -7,6 +9,7 @@ const securityPolicy = JSON.parse(
   await readFile("config/hosting/security-headers.json", "utf8"),
 );
 const baseUrl = process.env.HOSTING_BASE_URL;
+const liveTarget = baseUrl ? classifyLiveHostingBaseUrl(baseUrl) : null;
 const distFiles = (await readdir("dist", { recursive: true })).map(String);
 const publicSourceMaps = distFiles.filter((file) => file.endsWith(".map"));
 const publicServiceWorkers = distFiles.filter((file) =>
@@ -14,10 +17,19 @@ const publicServiceWorkers = distFiles.filter((file) =>
 );
 
 /** @type {Record<string, Record<string, string>>} */
-let responses;
+let responses = {};
 let mode;
+/** @type {Array<{
+ * surface: string;
+ * header: string;
+ * expected: unknown;
+ * observed: unknown;
+ * reason?: string;
+ * passed: boolean;
+ * }>} */
+const probeResults = [];
 
-if (baseUrl) {
+if (liveTarget?.passed) {
   mode = "live";
   const assets = await readdir("dist/assets");
   const hashedJavaScript = assets.find((file) => file.endsWith(".js"));
@@ -30,14 +42,52 @@ if (baseUrl) {
   };
   responses = {};
   for (const [surface, pathname] of Object.entries(paths)) {
-    const response = await fetch(new URL(pathname, baseUrl));
-    responses[surface] = Object.fromEntries(
-      [...response.headers.entries()].map(([name, value]) => [
-        name.toLowerCase(),
-        value,
-      ]),
-    );
+    const requestedUrl = new URL(pathname, liveTarget.url);
+    try {
+      const response = await fetch(requestedUrl, { redirect: "follow" });
+      const finalUrl = new URL(response.url);
+      probeResults.push(
+        {
+          surface,
+          header: "http-status",
+          expected: 200,
+          observed: response.status,
+          passed: response.status === 200,
+        },
+        {
+          surface,
+          header: "final-origin",
+          expected: liveTarget.url.origin,
+          observed: finalUrl.origin,
+          passed: finalUrl.origin === liveTarget.url.origin,
+        },
+      );
+      responses[surface] = Object.fromEntries(
+        [...response.headers.entries()].map(([name, value]) => [
+          name.toLowerCase(),
+          value,
+        ]),
+      );
+    } catch (error) {
+      probeResults.push({
+        surface,
+        header: "transport",
+        expected: "reachable",
+        observed: error instanceof Error ? error.name : "UnknownError",
+        passed: false,
+      });
+    }
   }
+} else if (liveTarget) {
+  mode = "invalid-live";
+  probeResults.push({
+    surface: "deployment",
+    header: "base-url",
+    expected: "canonical non-loopback HTTPS root URL",
+    observed: liveTarget.observedOrigin,
+    reason: liveTarget.reason,
+    passed: false,
+  });
 } else {
   mode = "fixture";
   responses = JSON.parse(
@@ -45,7 +95,7 @@ if (baseUrl) {
   ).responses;
 }
 
-const results = [];
+const results = [...probeResults];
 for (const [surface, policy] of Object.entries(cachePolicy.surfaces)) {
   if (!("cacheControl" in policy)) continue;
   const observed = responses[surface]?.["cache-control"];
@@ -110,7 +160,7 @@ await writeFile(
       schemaVersion: 1,
       generatedAt: new Date().toISOString(),
       mode,
-      baseUrl: baseUrl ?? null,
+      baseUrl: liveTarget?.observedOrigin ?? null,
       providerVerificationRequired: mode !== "live",
       results,
       passed,