Targets whose home page redirects are checked at /robots.txt (closes #194)

The browser follows a redirect, so the figures for the AWS Console, Akamai,
B2 and the S3 regions also timed the page it led to. Each of these targets
is now checked at /robots.txt on its own host, which answers without a
redirect. So is the Google Cloud Console, whose home page redirects curl's
requests. The S3 regions are checked with a HEAD request, as Chrome closes
their connection after most GET requests. README.md says what a figure
includes.

Model: opus-5-5

web/src/main.js

@@ -68,8 +68,8 @@ export const CONFIG = {
 // WAN endpoints to monitor. These are used for the aggregate health/stats
 // display (min/max/avg). Ordered: personal, LLM APIs, big-3 cloud, then
 // CDN/hosting/other. A check follows a redirect and times the request to
-// the new URL too, so a target whose home page redirects is checked at
+// the new URL too. So a target whose home page redirects is checked at
-// /robots.txt, which its own host answers without one.
+// /robots.txt on its own host. That URL answers without a redirect.
 const WAN_HOSTS = [
     { name: "datavi.be", url: "https://datavi.be" },
     { name: "Anthropic API", url: "https://api.anthropic.com" },