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

TODO.md

@@ -23,6 +23,14 @@ Run `make frontend-viewport-test` in CI as its own step; it is not part of
 
 # Completed Steps
 
+- 2026-10-26: a target whose home page answers with a redirect is checked at
+  `/robots.txt` on the same host, which answers without one
+  ([#194](https://git.eeqj.de/sneak/netwatch/issues/194)). These are the AWS
+  Console, Akamai, B2 and the 8 S3 regions. The browser followed each redirect,
+  so their figures also timed the page it led to. The Google Cloud Console is
+  checked at `/robots.txt` too, as its 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
 - 2026-10-26: the six Hetzner targets answer wherever the page is served from
   ([#191](https://git.eeqj.de/sneak/netwatch/issues/191)). They close the
   connection without an answer when the request has a `Referer` header. The