Footer no longer says IPv4 only (closes #111)

Each check is a fetch: the browser picks IPv4 or IPv6 for each WAN
host, and the local targets are IPv4 addresses, so "IPv4 only" was
wrong for the page as a whole. The footer's first line drops it and
its separator; the rest of the footer is unchanged. TODO.md moves this
to Completed Steps and the layout decision from Future Steps into Next
Step.

Model: opus-5-5

TODO.md

@@ -16,11 +16,16 @@ Docker image, and the Gitea workflow `.gitea/workflows/check.yml` runs
 
 # Next Step
 
-Take "IPv4 only" out of the page's footer, as nothing in the page limits a check
-to IPv4 ([#111](https://git.eeqj.de/sneak/netwatch/issues/111)).
+Decide whether the repo moves to the layout `REPO_POLICIES.md` gives, with
+`backend/` no longer repeating files from the root
+([#30](https://git.eeqj.de/sneak/netwatch/issues/30)).
 
 # Completed Steps
 
+- 2026-10-04: the page's footer no longer says "IPv4 only"
+  ([#111](https://git.eeqj.de/sneak/netwatch/issues/111)): each check is a
+  `fetch`, the browser picks IPv4 or IPv6 for each WAN host, and the local
+  targets are IPv4 addresses. The rest of the footer is unchanged
 - 2026-10-04: `README.md`, `TODO.md` and `test/viewport/README.md` say what the
   tree does (issue #24). The README's Getting Started leads with `make` targets;
   a new Backend section says what `netwatch-server` stores, its routes and how
@@ -384,9 +389,6 @@ to IPv4 ([#111](https://git.eeqj.de/sneak/netwatch/issues/111)).
 
 # Future Steps
 
-- Decide whether the repo moves to the layout `REPO_POLICIES.md` gives, with
-  `backend/` no longer repeating files from the root
-  ([#30](https://git.eeqj.de/sneak/netwatch/issues/30))
 - Run `make frontend-viewport-test` in CI as its own step; it is not part of
   `make check`, as it needs Docker and takes minutes
 - A backend test that posts a report to `POST /api/v1/reports` and checks the